Grade 8 Overview The Number System (NS) Know that there are numbers that are not rational, and approximate them by rational numbers. ( Standards 1and 2) Mathematical Practices (MP) 1. Make sense of problems and persevere in solving them. 2. Reason abstractly and quantitatively. 3. Construct viable arguments and critique the reasoning of others. 4. Model with mathematics. 5. Use appropriate tools strategically. 6. Attend to precision. 7. Look for and make use of structure. 8. Look for and express regularity in repeated reasoning. Expressions and Equations (EE) Work with radicals and integer exponents. (Standards 1, 2, 3, and 4) Understand the connections between proportional relationships, lines, and linear equations. (Standards 5 and 6) Analyze and solve linear equations and pairs of simultaneous linear equations. (Standards 7 and 8) Functions (F) Define, evaluate, and compare functions. (Standards 1, 2 and 3) Use functions to model relationships between quantities. (Standards 4 and 5) Geometry (G) Understand congruence and similarity using physical models, transparencies, or geometry software. (Standards 1, 2, 3, 4, and 5) Understand and apply the Pythagorean Theorem. (Standards 6, 7, and 8) Solve real-world and mathematical problems involving volume of cylinders, cones and spheres. (Standard 9) Statistics and Probability (SP) Investigate patterns of association in bivariate data. (Standards 1, 2, 3, and 4) *Numbers following cluster heading indicate standards included in the cluster. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 1 In Grade 8, instructional time should focus on three critical areas: (1) formulating and reasoning about expressions and equations, including modeling an association in bivariate data with a linear equation, and solving linear equations and systems of linear equations; (2) grasping the concept of a function and using functions to describe quantitative relationships; (3) analyzing two- and three-dimensional space and figures using distance, angle, similarity, and congruence, and understanding and applying the Pythagorean Theorem. (1) Students use linear equations and systems of linear equations to represent, analyze, and solve a variety of problems. Students recognize equations for proportions (y/x = m or y = mx) as special linear equations (y = mx + b), understanding that the constant of proportionality (m) is the slope, and the graphs are lines through the origin. They understand that the slope (m) of a line is a constant rate of change, so that if the input or xcoordinate changes by an amount A, the output or y-coordinate changes by the amount mA. Students also use a linear equation to describe the association between two quantities in bivariate data (such as arm span vs. height for students in a classroom). At this grade, fitting the model, and assessing its fit to the data are done informally. Interpreting the model in the context of the data requires students to express a relationship between the two quantities in question and to interpret components of the relationship (such as slope and y-intercept) in terms of the situation. Students strategically choose and efficiently implement procedures to solve linear equations in one variable, understanding that when they use the properties of equality and the concept of logical equivalence, they maintain the solutions of the original equation. Students solve systems of two linear equations in two variables and relate the systems to pairs of lines in the plane; these intersect, are parallel, or are the same line. Students use linear equations, systems of linear equations, linear functions, and their understanding of slope of a line to analyze situations and solve problems. (2) Students grasp the concept of a function as a rule that assigns to each input exactly one output. They understand that functions describe situations where one quantity determines another. They can translate among representations and partial representations of functions (noting that tabular and graphical representations may be partial representations), and they describe how aspects of the function are reflected in the different representations. (3) Students use ideas about distance and angles, how they behave under translations, rotations, reflections, and dilations, and ideas about congruence and similarity to describe and analyze two-dimensional figures and to solve problems. Students show that the sum of the angles in a triangle is the angle formed by a straight line, and that various configurations of lines give rise to similar triangles because of the angles created when a transversal cuts parallel lines. Students understand the statement of the Pythagorean Theorem and its converse, and can explain why the Pythagorean Theorem holds, for example, by decomposing a square in two different ways. They apply the Pythagorean Theorem to find distances between points on the coordinate plane, to find lengths, and to analyze polygons. Students complete their work on volume by solving problems involving cones, cylinders, and spheres. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 2 Standards for Mathematical Practice Standards Students are expected to: Explanations and Examples Mathematical Practices are listed throughout the grade level document in the 2nd column to reflect the need to connect the mathematical practices to mathematical content in instruction. 8.MP.1. Make sense of problems and persevere in solving them. 8.MP.2. Reason abstractly and quantitatively. 8.MP.3. Construct viable arguments and critique the reasoning of others. 8.MP.4. Model with mathematics. 8.MP.5. Use appropriate tools strategically. In grade 8, students solve real world problems through the application of algebraic and geometric concepts. Students seek the meaning of a problem and look for efficient ways to represent and solve it. They may check their thinking by asking themselves, “What is the most efficient way to solve the problem?”, “Does this make sense?”, and “Can I solve the problem in a different way?” In grade 8, students represent a wide variety of real world contexts through the use of real numbers and variables in mathematical expressions, equations, and inequalities. They examine patterns in data and assess the degree of linearity of functions. Students contextualize to understand the meaning of the number or variable as related to the problem and decontextualize to manipulate symbolic representations by applying properties of operations. In grade 8, students construct arguments using verbal or written explanations accompanied by expressions, equations, inequalities, models, and graphs, tables, and other data displays (i.e. box plots, dot plots, histograms, etc.). They further refine their mathematical communication skills through mathematical discussions in which they critically evaluate their own thinking and the thinking of other students. They pose questions like “How did you get that?”, “Why is that true?” “Does that always work?” They explain their thinking to others and respond to others’ thinking. In grade 8, students model problem situations symbolically, graphically, tabularly, and contextually. Students form expressions, equations, or inequalities from real world contexts and connect symbolic and graphical representations. Students solve systems of linear equations and compare properties of functions provided in different forms. Students use scatterplots to represent data and describe associations between variables. Students need many opportunities to connect and explain the connections between the different representations. They should be able to use all of these representations as appropriate to a problem context. Students consider available tools (including estimation and technology) when solving a mathematical problem and decide when certain tools might be helpful. For instance, students in grade 8 may translate a set of data given in tabular form to a graphical representation to compare it to another data set. Students might draw pictures, use applets, or write equations to show the relationships between the angles created by a transversal. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 3 Standards for Mathematical Practice Standards Students are expected to: Explanations and Examples Mathematical Practices are listed throughout the grade level document in the 2nd column to reflect the need to connect the mathematical practices to mathematical content in instruction. 8.MP.6. Attend to precision. 8.MP.7. Look for and make use of structure. 8.MP.8. Look for and express regularity in repeated reasoning. In grade 8, students continue to refine their mathematical communication skills by using clear and precise language in their discussions with others and in their own reasoning. Students use appropriate terminology when referring to the number system, functions, geometric figures, and data displays. Students routinely seek patterns or structures to model and solve problems. In grade 8, students apply properties to generate equivalent expressions and solve equations. Students examine patterns in tables and graphs to generate equations and describe relationships. Additionally, students experimentally verify the effects of transformations and describe them in terms of congruence and similarity. In grade 8, students use repeated reasoning to understand algorithms and make generalizations about patterns. Students use iterative processes to determine more precise rational approximations for irrational numbers. During multiple opportunities to solve and model problems, they notice that the slope of a line and rate of change are the same value. Students flexibly make connections between covariance, rates, and representations showing the relationships between quantities. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 4 Grade 8 The Number System (NS) 8.NS Know that there are numbers that are not rational, and approximate them by rational numbers. (Cluster 1- Standards 1 and 2) Essential Concepts Essential Questions The real numbers system contains both rational and irrational numbers. The set of rational numbers contain subsets of numbers that build on each other. Every rational number can be written as a ratio of two quantities a and as a decimal. b What types of numbers are in the real number system? How are the subsets of the rational numbers related to each other? What is the difference between a rational and irrational number? How do you estimate the value of an irrational number to help you solve problems? Every real number has a decimal expansion; rational numbers have a decimal expansion that will either terminate or repeat, where as irrational numbers have a decimal expansion that will not terminate or repeat. Square roots of perfect squares are rational numbers; where as square roots of non-perfect squares are irrational numbers. Irrational numbers (such as or 2 ) are estimated using truncated decimal expansions, in order to be able to compare and place them on a number line in order from least to greatest. 8.NS.1 Standard 8.NS.1. Know that numbers that are not rational are called irrational. Understand informally that every number has a decimal expansion; for rational numbers show that the decimal expansion repeats eventually, and convert a decimal expansion, which repeats eventually into a rational number. Mathematical Practices Examples & Explanations Students can use graphic organizers to show the relationship between the subsets of the real number system. 8.MP.2. Reason abstractly and quantitatively. 8.MP.6. Attend to precision. 8.MP.7. Look for and make use of structure. Connections: 8.EE.4; 8.EE.7b; 6-8.RST.4; 6-8.RST.7 Continued on next page Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 5 Students convert the fraction 2 to a decimal and determine if the number is rational or 3 0.66 2 32.00 0.66 so this is rational because it repeats. 3 Examples & Explanations irrational. 8.NS.2 Standard 8.NS.2. Use rational approximations of irrational numbers to compare the size of irrational numbers, locate them approximately on a number line diagram, and estimate the value of expressions (e.g., 2). For example, by truncating the decimal expansion of √2, show that √2 is between 1and 2, then between 1.4 and 1.5, and explain how to continue on to get better approximations. Connections: 8.G.7; 8.G.8; 68.RST.5; ET08-S1C2-01 Mathematical Practices 8. MP.2. Reason abstractly and quantitatively. Students approximate square roots by iterative processes. Examples: 8.MP.4. Model with mathematics. 5 to the nearest hundredth. Solution: Students start with a rough estimate based upon perfect squares. 5 falls between 2 and 3 because 5 falls between 22 = 4 and 32 = 9. The value will be closer to 2 than to3. Students continue the iterative process with the tenths place value. 8.MP.7. Look for and make use of structure. 8.MP.8. Look for and express regularity in repeated reasoning. Approximate the value of 5 falls between 2.2 and 2.3 because 5 falls between 2.22 = 4.84 and 2.32 = 5.29. The value is closer to 2.2. Further iteration shows that the value of 5 is between 2.23 and 2.24 since 2.232 is 4.9729 and 2.242 is 5.0176. By truncating the decimal expansion of √2, show that √2 is between 1and 2, then between 1.4 and 1.5, and explain how to continue on to get better approximations. Compare √2 and √3 by estimating their values, plotting them on a number line, and making comparative statements. Solution: Statements for the comparison could include: √2 is approximately 0.3 less than √3 √2 is between the whole numbers 1 and 2 √3 is between 1.7 and 1.8 Continued on next page Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 6 Additional Domain Information – The Number System (NS) Key Vocabulary Decimal expansion Estimate Fraction Integer Irrational number Iterative process Natural Number Number line Perfect Square Ratio Rational number Real Number Repeating decimal Square (x2) Square root Subset Terminating decimal Whole Number Example Resources Books HOLT (4.6, 4.7) Math In Context (Revisiting Numbers) Looking for Pythagoras CMP Lesson 2 In this investigation, students will explore the relationship between the side lengths and areas of squares and use that relationship to find the lengths of segments on dot grids. Technology Khan academy My.hrw.com http://www.internet4classrooms.com/grade_level_help/number_rational_irrational_math_eighth_8th_grade.htm Several links provide students with rational and irrational numbers and rational number subgroups. (Once link is opened, click “Impatient?” to open.) http://www.quia.com/cm/110177.html Students can sort numbers into rational and irrational numbers. http://tulyn.com/8th-grade-math/irrational-numbers This website has videos on irrational numbers. Exemplary Lessons http://www.lessonplanspage.com/mathcilaidentifyingandorderingrationalandirrationalnumbers8-htm/ An Excel spreadsheet is used in this rational and irrational number lesson. This lesson plan is part of a larger unit covering number sense and operations. The students have demonstrated proficiency at addition, subtraction, multiplication, and division of integers, decimals, and fractions. The objectives addressed in this lesson lead directly into the following objectives of identifying and ordering rational and irrational numbers. Students will; Learn definitions of rational numbers, terminating decimals, and repeating decimals, Express fractions as terminating or repeating decimals, Order rational numbers. http://alex.state.al.us/lesson_view.php?id=24079 Students will participate in an activity that will help them obtain a feeling of how numbers are related to each other. They will determine whether a number is rational or irrational. Students will also be able to order rational and irrational numbers on a number line. Students will determine if a number is rational or irrational. Students will be able to order rational and irrational numbers on a number line. Students will be able to locate square roots on a number line. http://www.homeschoolmath.net/teaching/irrational_numbers.php Most children learn about Pi and square roots somewhere during the middle school. They may hear said 'irrational number' and some even remember the phrase, but very few really understand what it means. Well, irrational numbers are harder to understand than rational numbers, but I consider it worth the time and effort because they have some fascinating properties. I just have to wonder in awe when I see the facts laid in front of me because it all sounds Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 7 unbelievable, yet proven true. Assessment All assessments for this domain must focus on assessing the degree, to which seventh grade students can, within the parameters specified in the 3 standards included in this domain, know that there are numbers that are not rational, and approximate them by rational numbers. Both formative and summative assessments are vital components of effective mathematics curricula. Formative assessments, (e.g., pre-assessments, daily checks for understanding, discussions of strategies students use to solve problems, etc.) assist in instructional planning and implementation; summative assessments (e.g., unit assessments, quarterly benchmarks, etc.) inform learner growth related to important mathematics concepts. All district-adopted resources contain multiple assessment tools and include online resources that can be used for the purposes delineated above. PARCC also will provide two end of the year summative assessments. The first, a performance-based assessment, will focus on applying skills, concepts, and understandings to solve multi-step problems requiring abstract reasoning, precision, perseverance, and strategic use of tools. The performance measure will be administered as close to the end of the school year as possible. The second, an end of the year machine-scorable summative assessment will be administered after approximately 90% of the school year. These assessments are to begin during the SY 2014-2015. Common Student Misconceptions Students fail to realize a ratio can be a fraction and all fractions are ratios: Explain to students that both ratios and fractions compare two quantities. However a ratio can express a part-to-whole comparison or a part-to-part comparison, where as a fraction is always a part-to-whole comparison. Students believe repeating decimals are irrational: Show the student examples of fractions that are repeating decimals, such as 1/3. Because the repeating decimal can be written as a fraction, by definition, makes it a rational number. Students commonly believe that decimals with a pattern are rational. For example, students often think 0.010010001… is rational. This decimal is great example to show students. They know what is coming next, however it does not repeat and therefore is irrational. Students often misunderstand the relationship between rational numbers and its subgroups. Show examples of natural numbers, whole numbers, and integers and how they relate to each other. The graphic organizer of nested subsets or a foldable is a powerful way to show the relationships. Students do not see the fraction bar as an operation: A fraction is a division problem and a division problem can be represented with a fraction. Students do not see irrational numbers as numbers that do not repeat or terminate. Some students are surprised that the decimal representation of Pi does not repeat. Some students believe that if only we keep looking at digits farther to the right, eventually a pattern will emerge. A few irrational numbers are given special names (Pi and e), and much attention is given to square root of 2. Because we name so few irrational numbers, students sometimes conclude that irrational numbers are unusual and rare. In fact, irrational numbers are much more plentiful than rational numbers in the sense that they are “denser” in the real number system. Using square roots of non perfect squares is a powerful way to explain this. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 8 Grade 8 Expressions and Equations (EE) (3 Clusters) 8.EE Work with radicals and integer exponents(Cluster 1-Standards 1,2,3, and 4) Essential Concepts Essential Questions Properties of integer exponents are used to simplify and create equivalent forms of numerical expressions. The inverse operation of squaring a number is finding the square root. The inverse operation of cubing a number is finding the cube root. Very large and very small numbers are represented using a single digit times an integer power of 10 (scientific notation). Decimal form can be converted to scientific notation and vice-versa. Operations and rules for exponents are used to determine the value and/or compare numbers in both decimal and scientific notation. Calculators and computers display scientific notation in different formats. 8.EE.1 Standard 8.EE.1 Know and apply the properties of integer exponents to generate equivalent numerical expressions. For example, 323–5 = 3–3 = 1/33 = 1/27. Mathematical Practices Examples: 8.MP.5. Use appropriate tools strategically. 8.MP.7. Look for and make use of structure. How do you use properties of integer exponents to simplify a numerical expression? Why would you want to simplify a numerical expression with integer exponents? What is the relationship between squares and square roots? Cube and cube roots? What is scientific notation? Why would you want to use scientific notation to compare very large or very small numbers? How do you convert numbers between scientific notation and decimal form or vice-versa? How is scientific notation generated (shown) by technology? Examples & Explanations 8.MP.2. Reason abstractly and quantitatively. 8.MP.6. Attend to precision. 43 52 43 47 64 25 1 1 43 7 4 4 256 44 4-3 1 1 1 1 1 1 = 4-3 ´ 2 = 3 ´ 2 = ´ = 2 5 5 4 5 64 25 16, 000 323–5 = 3–3 = 1/33 = 1/27. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 9 8.EE Work with radicals and integer exponents(Cluster 1-Standards 1,2,3, and 4) 8.EE.2 Standard 8.EE.2 Use Mathematical Examples & Explanations square root and cube root Examples: Practices 2 symbols to represent 8.MP.2. Reason 3 9 and 9 3 solutions to equations of the form x2 = p and x3 = p, where p is a positive rational number. Evaluate square roots of small perfect squares and cube roots of small perfect cubes. Know that √2 is irrational. Connections: 8.G.7; 8.G.8; 68.RST.4 abstractly and quantitatively. 13 1 1 and 3 3 3 27 2 Solve x 9 2 Solution: x 9 3 8.MP.5. Use appropriate tools strategically. 3 1 27 3 3 1 27 1 3 x2 = ± 9 x 3 8.MP.6. Attend to precision. 8.MP.7. Look for and make use of structure. Solve x 8 3 Solution: x 8 3 x3 3 8 3 x2 Know that √2 is irrational. 8.EE.3 Standard 8.EE.3 Use numbers expressed in the form of a single digit times an integer power of 10 to estimate very large or very small quantities, and to express how many times as much one is than the other. For example, estimate the population of the United States as 3108 and the population of the world as 7109, and determine that the world population is more than 20 times larger. Mathematical Practices 8.MP.2. Reason abstractly and quantitatively. 8.MP.5. Use appropriate tools strategically. Examples & Explanations Students have previously worked with powers of 10 and decimal placement in 5th grade. For example in 5th grade they look at the patterns on placement of the decimal points when a decimal is multiplied or divided by a positive power of ten. o Example from 5th grade document page 7 “Students should be able to use the same type of reasoning as above to explain why the following multiplication and division problem by powers of 10 make sense. 523 10 3 523,000 The place value of 523 is increased by 3 places. 8.MP.6. Attend to precision. 5.223 102 522.3 The place value of 5.223 is increased by 2 places. 52.3 101 5.23 The place value of 52.3 is decreased by one place.” Continued on next page Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 10 8.EE.4 Standard 8.EE.4 Perform operations with numbers expressed in scientific notation, including problems where both decimal and scientific notation are used. Use scientific notation and choose units of appropriate size for measurements of very large or very small quantities (e.g., use millimeters per year for seafloor spreading). Interpret scientific notation that has been generated by technology. Mathematical Practices 8.MP.2. Reason abstractly and quantitatively. 8.MP.5. Use appropriate tools strategically. Estimate the population of the United States as 3108 and the population of the world as 7109, and determine that the world population is more than 20 times larger. Examples & Explanations Students can convert decimal forms to scientific notation and apply rules of exponents to simplify expressions. In working with calculators or spreadsheets, it is important that students recognize scientific notation. Students should recognize that the output of 2.45E+23 is 2.45 x 10 23 and 3.5E-4 is 3.5 x 10-4. Students enter scientific notation using E or EE (scientific notation), * (multiplication), and ^ (exponent) symbols. 8.MP.6. Attend to precision. Connections: 8.NS.1; 8.EE.1; ET08-S6C1-03 8.EE Understand the connections between proportional relationships, lines, and linear equations (Cluster 2- Standards 5, 6, and 7) Essential Concepts Essential Questions A proportional relationship has a constant rate of change (or unit rate), known as the slope. Equations for proportional relationships are linear equations of the form y=mx, where m is the unit rate or slope. Linear equations when graphed are straight lines. Proportional relationship when graphed, are straight lines that goes through the origin. Proportional relationships can be compared using graphs, tables, and equations by analyzing the slopes (unit rates). Equations for linear relationship are of the form y=mx, where m is the unit rate or slope and goes through the origin or y=mx+b for a line intercepting the vertical axis at b. Proportional relationships are a special form of a linear relationship. Tucson Unified School District Mathematics Curriculum How are proportional relationships represented on a graph, a table and an equation? How do you compare different proportional relationships represented on graphs, tables and equations? What is the difference between a proportional relationship and a linear relationship on a graph? Equation? How do you show that the slope is the same between any two distinct points on a non- vertical line in the coordinate plane? How can you determine if a linear equation has one solution, infinitely many or no solutions? What is the significance of the slope in a linear equation? Continued on next page Grade 8 Board Approved 03/27/2012 11 The slope m is the same between any two distinct points on a nonvertical line in the coordinate plane. (This is shown using similar triangles.) Linear equations in one variable have one solution, infinitely many solutions or no solutions. Linear equations can be expanded and simplified using the distributive property and combining like terms. 8.EE.5 Standard 8.EE.5 Graph proportional relationships, interpreting the unit rate as the slope of the graph. Compare two different proportional relationships represented in different ways. For example, compare a distance-time graph to a distance-time equation to determine which of two moving objects has greater speed. Connections: 8.F.2; 8.F.3; 68.RST.7; 6-8.WHST.2b; SC08-S5C2-01; SC08-S5C205 Mathematical Practices 8.MP.1. Make sense of problems and persevere in solving them. 8.MP.2. Reason abstractly and quantitatively. 8.MP.3. Construct viable arguments and critique the reasoning of others. Examples & Explanations Using graphs of experiences that are familiar to students’ increases accessibility and supports understanding and interpretation of proportional relationship. Students are expected to both sketch and interpret graphs. Example: Compare a distance-time graph to a distance-time equation to determine which of two moving objects has greater speed. Compare the scenarios to determine which represents a greater speed. Include a description of each scenario including the unit rates in your explanation. Scenario 1: Scenario 2: Scenario 1: y = 50x x is time2:in hours Scenario y is distance in miles 8.MP.4. Model with mathematics. 8.MP.5. Use appropriate tools strategically. 8.MP.6. Attend to precision. 8.MP.7. Look for and make use of structure. Continued on next page Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 12 8.MP.8. Look for and express regularity in repeated reasoning. 8.EE.6 Standard 8.EE.6 Use similar triangles to explain why the slope m is the same between any two distinct points on a nonvertical line in the coordinate plane; derive the equation y = mx for a line through the origin and the equation y = mx + b for a line intercepting the vertical axis at b. Connections: 8.F.3; 8.G.4; 68.RST.3; 6-8.WHST.1b; ET08-S1C201; ET08-S6C1-03 Mathematical Practices 8.MP.2. Reason abstractly and quantitatively. 8.MP.3. Construct viable arguments and critique the reasoning of others. Examples & Explanations Example: If you take two pairs of points on the same line, and then draw the corresponding triangles, the triangles will be similar. Because the triangles are similar the ratio of side length must therefore be the same, thus showing that slope between either pair of points is the same. Explain why ACB is similar to DFE , and deduce that AB has the same slope as BE . Express each line as an equation. 8.MP.4. Model with mathematics. 8.MP.5. Use appropriate tools strategically. 8.MP.7. Look for and make use of structure. 8.MP.8. Look for and express regularity in repeated reasoning. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 13 8.EE Understand the connections between proportional relationships, lines, and linear equations (Cluster 2- Standards 5, 6, and 7) 8.EE.7 Standard 8.EE.7 Mathematical Examples & Explanations Solve linear equations in one As students transform linear equations in one variable into simpler forms, they discover the Practices variable. a. Give examples of linear equations in one variable with one solution, infinitely many solutions, or no solutions. Show which of these possibilities is the case by successively transforming the given equation into simpler forms, until an equivalent equation of the form x = a, a = a, or a = b results (where a and b are different numbers). b. Solve linear equations with rational number coefficients, including equations whose solutions require expanding expressions using the distributive property and collecting like terms. 8.MP.2. Reason abstractly and quantitatively. 8.MP.5. Use appropriate tools strategically. 8.MP.6. Attend to precision. 8.MP.7. Look for and make use of structure. Connections: 8.F.3; 8.NS.1; 6-8.RST.3; ET08-S1C3-01 equations can have one solution, infinitely many solutions, or no solutions. When the equation has one solution, the variable has one value that makes the equation true as in 12-4y=16. The only value for y that makes this equation true is -1. When the equation has infinitely many solutions, the equation is true for all real numbers as in 7x + 14 = 7 (x+2). As this equation is simplified, the variable terms cancel leaving 14 = 14 or 0 = 0. Since the expressions are equivalent, the value for the two sides of the equation will be the same regardless which real number is used for the substitution. When an equation has no solutions it is also called an inconsistent equation. This is the case when the two expressions are not equivalent as in 5x - 2 = 5(x+1). When simplifying this equation, students will find that the solution appears to be two numbers that are not equal or -2 = 1. In this case, regardless which real number is used for the substitution, the equation is not true and therefore has no solution. Examples: Solve for x: o 3( x 7) 4 o o 3x 8 4x 8 3( x 1) 5 3x 2 Solve: o 7( m 3) 7 o 1 2 3 1 y y 4 3 4 3 Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 14 8.EE Analyze and solve linear equations and pairs of simultaneous linear equations (Cluster 3- Standard 8) Essential Concepts Essential Questions The solution to a system of linear equations in two variables is the point/ ordered pair on a graph where the two lines will intersect. The solution to a system of linear equations in two variables is the point/ ordered pair that satisfies both equations. System of linear questions can be solved algebraically to find the point of intersection and then checked graphically. 8.EE.8 Standard 8.EE.8 Analyze and solve pairs of simultaneous linear equations. a. Understand that solutions to a system of two linear equations in two variables correspond to points of intersection of their graphs, because points of intersection satisfy both equations simultaneously. b. Solve systems of two linear equations in two variables algebraically, and estimate solutions by graphing the equations. Solve simple cases by inspection. For example, 3x + 2y = 5 and 3x + 2y = 6 have no solution because 3x + 2y cannot simultaneously be 5 and 6. c. Solve real-world and mathematical problems leading to two linear equations in two variables. For example, given coordinates for two Mathematical Practices 8.MP.1. Make sense of problems and persevere in solving them. 8.MP.2. Reason abstractly and quantitatively. 8.MP.3. Construct viable arguments and critique the reasoning of others. 8.MP.4. Model with mathematics. 8.MP.5. Use appropriate tools strategically. How do you determine the solution to a system of linear equations on a graph? Algebraically? Do all system of linear equations have a solution? How do yow know? What is an example of a real – world problem that can be solved using a system of linear equations? How do you determine if a given point is a solution to a system of linear equations? Examples & Explanations A system of linear equations in two variables can be solved by graphing the two equations and finding the point of intersection. Student may also discover, by graphing, that some systems will never intersect because the lines are parallel. Therefore these systems will not have a solution. A system of linear equations can also be solved algebraically using substitution. There are two ways to solve using substitution. 1.) Given two equations equal to the same variable. For example: C = 2x + 7 and C = 3x + 5 Set these two equations equal to each other and solve for the unknown (in this case x.) 2x+7 = 3x + 5 2.) Given two equations in which one equation is solved for a given variable. For example: x = 7 + y and 3x + 2y = 6 Substitute 7+ y in for the x in 3x+2y = 6 that is 3(7+y) + 2y = 6 and solve for y. Once you have solved for one variable, plug that answer into one of the original equations to find the missing coordinate in the ordered pair. Every solution to a system of linear equations should be given as an ordered pair with two variables. To check whether a given a point/ ordered pair is a solution to a system of linear equations, substitute the values in each equation and simplify to be sure the statements are true. Example: Check whether (4, -3) is solution to the system x = 7 + y and 3x+2y = 6 3x 2y 6 x 7 y 8.MP.6. Attend to precision. That is 8.MP.7. Look for and make use of structure. Tucson Unified School District Mathematics Curriculum 4 7 (3) 44 True 15 3(4) 2(3) 6 and 12 6 6 Therefore (4,-3) is a solution to the system! 66 True Grade 8 Board Approved 03/27/2012 pairs of points, determine whether the line through the first pair of points intersects the line through the second pair. 8.MP.8. Look for and express regularity in repeated reasoning. PLEASE NOTE! “The standard does say that students should solve systems algebraically, although it doesn't specify a method, so I wouldn't say they have to know both substitution and elimination, and a full-blown treatment comes later.” Bill McCallum (chief author of CCSS). Connections: 6-8.RST.7; ET08-S1C2-01; ET08-S1C2-02 Continued on next page Examples: Solve simple cases by inspection. For example, 3x + 2y = 5 and 3x + 2y = 6 have no solution because 3x + 2y cannot simultaneously be 5 and 6. Given coordinates for two pairs of points, determine whether the line through the first pair of points intersects the line through the second pair. Plant A and Plant B are on different watering schedules. This affects their rate of growth. Compare the growth of the two plants to determine when their heights will be the same. Let W = number of weeks Let H = height of the plant after W weeks W 0 1 2 3 Plant A H 4 6 8 10 (0,4) (1,6) (2,8) (3,10) W 0 1 2 3 Plant B H 2 6 10 14 (0,2) (1,6) (2,10) (3,14) Given each set of coordinates, graph their corresponding lines. Solution: Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 16 Continued on next page Write an equation that represent the growth rate of Plant A and Plant B. Solution: Plant A H = 2W + 4 Plant B H = 4W + 2 At which week will the plants have the same height? Solution: The plants have the same height after one week. Plant A: H = 2W + 4 Plant B: H = 4W + 2 Plant A: H = 2(1) + 4 Plant B: H = 4(1) + 2 Plant A: H = 6 Plant B: H = 6 After one week, the height of Plant A and Plant B are both 6 inches. Additional Domain Information – Expressions and Equations (EE) Key Vocabulary (BOLD means most important) Base Cube Cube Root Exponent Exponential form Perfect Square Power Radical Scientific notation Square Square root Example Resources Book HOLT (Chapter 4.1-4.5, 11 and 12 and extension) Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 17 Math In Context (Revisiting Numbers, Algebra Rules!, Graphing Equations) CMP2 (8th grade: Looking or Pythagoras inv 2, 7th grade: Moving Straight Ahead) Algebra 1 book (8.1-8.4,3.1-3.4, chapter 4-5 and 6.1) Technology http://nlvm.usu.edu/en/nav/category_g_3_t_2.html Virtual manipulatives for exponents and equations under algebra. http://www.geogebra.org/cms/ Mathematics software for learning and teaching. http://www.ixl.com/math/grade-8 Practice skills for exponents and roots, scientific notation, single variable equations, and linear functions. http://www.mrbartonmaths.com/algebra.htm Collecting Like Terms/Simplifying, Indices, Misconceptions, Solving Equations, Straight Line Graphs, Substitution, Writing Expressions. https://eee.uci.edu/wiki/index.php/*Algebra_and_Functions Common misconceptions in algebra. Exemplary Lessons http://usablealgebra.landmark.edu/designing-evaluating-resources/sample-lesson-plan-exponents/ This exponent lesson plan provides goals, lessons and methods with online resources for students. In the lesson students will perform operations using real numbers and variables; add, subtract, multiply, and divide signed numbers, write numbers in exponent form and evaluate numerical expressions that contain exponents. http://www.curriki.org/xwiki/bin/view/Coll_MSP2/AlgebraicThinkingABasicSkill The resources highlighted here aim to reflect students' growing mathematical capacity over the span of the middle school years. The activities and lessons, intended as supplementary materials, range from introduction to the fundamentals of algebra to work on linear functions. Uniformly, they take into consideration the preference of the middle school student for concrete models, visual representations, and interactive tasks. You will find resources on: working with algebraic expressions, solving equations, understanding graphs, moving from patterns to rules to functions. Some are games, others are online simulations that can complement a lesson, and yet others are full- blown lesson plans. We believe you will find tasks here that motivate your students to expand their basic skills in algebra. http://www.beaconlearningcenter.com/lessons/1669.htm This scientific notation lesson plan includes attached materials and extension lessons. It is hard to envision the distance to the Moon without thinking about a very large number. Yet, a lunar dust particle is so small, several fit on the tip of a pinhead! Students explore the extreme solving problems related to the Apollo space missions. http://www.realworldmath.org/Real_World_Math/Lessons.html Teachers choose plans by lesson type which uses Google Earth. Concept lessons will use Google Earth to present math topics, such as rates or scientific notation in unique ways. Project-Based Learning activities will include lessons that will require the collaborative efforts of students in pairs or groups. These lessons may be of a longer duration and require additional outsource materials. Measurement lessons will make extensive use of the Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 18 ruler tool in Google Earth to accomplish problem solving activities. Exploratory lessons will follow non-traditional math topics such as fractals, topology, or modern geometry. Assessments All assessments for this domain must focus on assessing the degree, to which seventh grade students can, within the parameters specified in the 3 standards included in this domain, work with radicals and integer exponents, demonstrate an understanding of the connections between proportional relationships, lines, and linear equations, and analyze and solve linear equations and pairs of simultaneous linear equations. Both formative and summative assessments are vital components of effective mathematics curricula. Formative assessments, (e.g., pre-assessments, daily checks for understanding, discussions of strategies students use to solve problems, etc.) assist in instructional planning and implementation; summative assessments (e.g., unit assessments, quarterly benchmarks, etc.) inform learner growth related to important mathematics concepts. All district-adopted resources contain multiple assessment tools and include online resources that can be used for the purposes delineated above. PARCC also will provide two end of the year summative assessments. The first, a performance-based assessment, will focus on applying skills, concepts, and understandings to solve multi-step problems requiring abstract reasoning, precision, perseverance, and strategic use of tools. The performance measure will be administered as close to the end of the school year as possible. The second, an end of the year machine-scorable summative assessment will be administered after approximately 90% of the school year. These assessments are to begin during the SY 2014-2015. Common Student Misconceptions Students commonly think that an exponent means to multiply the base times the exponent. For example, students think that 32 = 3x2 as opposed 3 to 3x3 or 23 to be 2 x 3 instead of (2)(2)(2). Students need to understand the fact that, x , means x x x, means x times x times x, not 3x or 3 times x. 2 Students mistakenly apply the sign of the exponent to the base, that is students think x -n = -xn . For example, students believe 3 1 2 as 3 or -9 instead of 2 132 or 19. Patterns are a great way to show theprogression from positive exponents to negative exponents. 3 to be the same a symbol. For example, Students do not understand that square root problems have two possible answers and this should be denoted using 25 , there are two possible answers, 5 or -5. So when solving a problem such as x 2 25 students square root of both sides leaving x 25 . By using the they are showing they understand that there are two possible answers, one should take the positive and one negative. Students commonly confuse the product with exponents, of powers property and the power of a power property. When multiplying variables 2 3 is equivalent to x6 as students misinterpret the operation of the variables as the operation of the exponents. For example, students believe that x ⋅ x if students are asked to find the square root of 25, opposed to x5. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 19 Students believe that in scientific notation, when a number contains one nonzero digit and a positive exponent, the number of zeros equals the exponent. For example, 2,300,000 – 2.3 x 105. This pattern may incorrectly be applied to scientific notation values with negative values or with more than one nonzero digit. Students commonly believe that the E on a calculator display means an error as opposed to an exponent in scientific notation. Students believe that only the letters x and y can be used for variables: Explain to students the definition of a variable. Tell them that, while any variable can be used, some are more common than others. Students think that variables always have one specific value. Students solve one equation for x and find that x= 2. Then they think that x will always be 2. Students need to understand that variables can change value based on a given problem. For example, in x + 5 =10, x =5 but in x + 3 = 4 now x =1. Another example; p + q = 12; p and q have multiple values based what number type is being utilized. Students believe the variable is always on the left side of the equation: Students think that you always need a variable = a constant as a solution. Providing several examples with the variable on the left and right side of the equation will help students to recognize that it does not matter which side the variable is on. Students commonly combine unlike terms such as 5x+ 2y. Student may answer the question as 7xy. Here they do not understand the concept of like terms and the order of operations. Another common error is to say that 4x+6 = 10x. Again this stems from not understanding that the multiplication needs to be done before the addition. When students are simplifying expression with the distributive property, students commonly don’t multiply and show x x x . For example, given the problem 2x(5x+3) student commonly give the answer 10x +6x as opposed to 10x 2 + 6x. 2 As students begin to build and work with expressions containing more than two operations, students tend to set aside the order of operations. For example, having a student simplify an expression like 8 + 4(2x - 5) + 3x can bring to light several misconceptions. Do the students immediately add the 8 and 4 before distributing the 4? Do they only multiply the 4 and the 2x and not distribute the 4 to both terms in the parenthesis? Do they collect all like terms? Students commonly forget that the negative sign in front of a variable is really a coefficient of -1. For example, –x is really -1x. Students may think that the notation 4x means forty-something. For example, when evaluating 3x + 4 if x = 5, substitution does not result in the expression meaning 35 +4, students need to understand that 3x means x multiplied by 3 or x+x+x. Using parentheses when substituting in the value can prevent some of this confusion. For example, 3(5) + 4 = 15+4 =19. Students forget to combine like numbers to write the equation in slope intercept form: Equations are not always in the slope intercept form, y=mx+b. For example, 4x +5x + 9 +1 = y can be written as 9x +10 = y. Students confuse one-variable and two-variable equations. Students should be able to plug an ordered pair into two-variable equations to see if the equation is true, or to compare it to another equation to see if they are both equal. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 20 Functions (F) (2 Clusters) 8.F Define, evaluate, and compare functions (Cluster 1- Standards 1, 2, and 3) Essential Concepts Essential Questions A function is a rule that assigns each input exactly one output. A graph of an equation is also the graph of that function consisting of inputs and the corresponding outputs. Functions can be represented algebraically, graphically, numerically in tables or by verbal descriptions. Linear functions are represented by the equation y=mx+b and a straight line on a graph. 8.F.1 Standard 8.F.1 Understand that a function is a rule that assigns to each input exactly one output. The graph of a function is the set of ordered pairs consisting of an input and the corresponding output. (Function notation is not required in Grade 8.) Mathematical Practices 8.MP.2. Reason abstractly and quantitatively. 8.MP.6. Attend to precision. Connection: SC08-S5C2-05 Given a table or graph, how do determine if it represents a function? How do you compare properties of functions that are represented in different ways? How do you determine if an equation represents linear function? Give an example of a function that is not a linear function; explain why it is a function but not a linear function. Examples & Explanations For example, the rule that takes x as input and gives x2+5x+4 as output is a function. Using y to stand for the output we can represent this function with the equation y = x2+5x+4, and the graph of the equation is the graph of the function. Students are not yet expected use function notation such as f(x) = x2+5x+4. Example: Determine which if the following tables represent a function and explain why. A B Input Output Input Output 0 1 0 0 1 2 1 2 2 2 1 3 3 4 4 5 Solution: A represents a function because for each input there is exactly one output. B doe NOT represent a function because the input 1 has two outputs (2 and 3). Explanation: A vertical line test can be preformed to determine whether a graph represents a function. By definition a function, each x value (input) of a function can have only one y value (output). If a vertical line is drawn for an x value then that line can only hit the graph at one point (that is one output). Continued on next page Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 21 Example: Determine if the graph represents a function: A B C Solution: A & B are functions because the vertical line only hits the graph at one point no matter where you draw the line C is not a function because the vertical line hits the graph in two points. Continued on next page Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 22 8.F Define, evaluate, and compare functions (Cluster 1- Standards 1, 2, and 3) 8.F.2 Standard 8.F.2 Mathematical Examples & Explanations Compare properties of two Examples: Practices functions each represented in a different way (algebraically, graphically, numerically in tables, or by verbal descriptions). For example, given a linear function represented by a table of values and a linear function represented by an algebraic expression, determine which function has the greater rate of change. Connections: 8.EE.5; 8.F.2; 6-8.RST.7; 6-8.WHST.1b; ET08-S1C3-01 8.MP.1. Make sense of problems and persevere in solving them. Given a linear function represented by a table of values and a linear function represented by an algebraic expression, determine which function has the greater rate of change. Compare the two linear functions listed below and determine which equation represents a greater rate of change. 8.MP.2. Reason abstractly and quantitatively. Function 1: Function 2: 8.MP.3. Construct viable arguments and critique the reasoning of others. The function whose input x and output y are related by y = 3x + 7 8.MP.4. Model with mathematics. 8.MP.5. Use appropriate tools strategically. 8.MP.6. Attend to precision. 8.MP.7. Look for and make use of structure. 8.MP.8. Look for and express regularity in repeated reasoning. Compare the two linear functions listed below and determine which has a negative slope. Function 1: Gift Card Samantha starts with $20 on a gift card for the book store. She spends $3.50 per week to buy a magazine. Let y be the amount remaining as a function of the number of weeks, x. x 0 1 2 3 4 Continued on next page Tucson Unified School District Mathematics Curriculum y 20 16.50 13.00 9.50 6.00 Grade 8 Board Approved 03/27/2012 23 Function 2: The school bookstore rents graphing calculators for $5 per month. It also collects a non-refundable fee of $10.00 for the school year. Write the rule for the total cost (c) of renting a calculator as a function of the number of months (m). Solution: Function 1 is an example of a function whose graph has negative slope. Samantha starts with $20 and spends money each week. The amount of money left on the gift card decreases each week. The graph has a negative slope of -3.5, which is the amount the gift card balance decreases with Samantha’s weekly magazine purchase. Function 2 is an example of a function whose graph has positive slope. Students pay a yearly nonrefundable fee for renting the calculator and pay $5 for each month they rent the calculator. This function has a positive slope of 5 which is the amount of the monthly rental fee. An equation for Example 2 could be c = 5m + 10. 8.F.3 Standard 8.F.3 Interpret the equation y = mx + b as defining a linear function, whose graph is a straight line; give examples of functions that are not linear. For example, the function A = s2 giving the area of a square as a function of its side length is not linear because its graph contains the points (1,1), (2,4) and (3,9), which are not on a straight line. Connections: 8.EE.5; 8.EE.7a ; 6-8.WHST.1b; ET08-S6C103 Mathematical Practices 8.MP.2. Reason abstractly and quantitatively. 8.MP.4. Model with mathematics. 8.MP.5. Use appropriate tools strategically. Examples & Explanations Example: The function A = s2 giving the area of a square as a function of its side length is not linear because its graph contains the points (1,1), (2,4) and (3,9), which are not on a straight line. Determine which of the functions listed below are linear and which are not linear and explain your reasoning. o o o o y = -2x2 + 3 y = 2x A = πr2 y = 0.25 + 0.5(x – 2) non linear linear non linear linear 8.MP.6. Attend to precision. 8.MP.7. Look for and make use of structure. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 24 8.F Use functions to model relationships between quantities (Cluster 2- Standards 4 and 5) Essential Concepts Essential Questions Linear functions are functions that have a constant rate of change (slope) and an initial value. The initial value of a linear function is the place where the line will intersect the vertical axis or the y-intercept. Linear functions are represented as verbal descriptions, tables, graphs and equations that are all related by the same rate of change (slope) and initial value. Real world functional relationships between two quantities can be represented using verbal descriptions and graphs. 8.F.4 Standard 8.F.4 Construct a function to model a linear relationship between two quantities. Determine the rate of change and initial value of the function from a description of a relationship or from two (x, y) values, including reading these from a table or from a graph. Interpret the rate of change and initial value of a linear function in terms of the situation it models, and in terms of its graph or a table of values. Connections: 8.EE.5; 8.SP2; 8.SP.3; ET08-S1C2-01; SC08-S5C201; SC08-S1C3-02 Mathematical Practices 8.MP.1. Make sense of problems and persevere in solving them. 8.MP.2. Reason abstractly and quantitatively. 8.MP.3. Construct viable arguments and critique the reasoning of others. 8.MP.4. Model with mathematics. What are the attributes of a function that tell you it is a linear function? How do you find the rate of change and initial value of a linear function from the verbal description, table, graph or equation? How do write an equation for a linear function given a table? Graph? Verbal description? How do you determine if an equation, a table and a graph are related? Why would you want to represent a real world functional relationship with a graph? Examples & Explanations Examples: The table below shows the cost of renting a car. The company charges $45 a day for the car as well as charging a one-time $25 fee for the car’s navigation system (GPS).Write an expression for the cost in dollars, c, as a function of the number of days, d. Students might write the equation c = 45d + 25 using the verbal description or by first making a table. Days (d) 1 2 3 4 Cost (c) in dollars 70 115 160 205 Students should recognize that the rate of change is 45 (the cost of renting the car) and that initial cost (the first day charge) also includes paying for the navigation system. Classroom discussion about one time fees vs. recurrent fees will help students model contextual situations. 8.MP.5. Use appropriate tools strategically. Continued on next page Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 25 8.MP.6. Attend to precision. 8.MP.7. Look for and make use of structure. 8.MP.8. Look for and express regularity in repeated reasoning. 8.F.5 Standard 8.F.5 Describe qualitatively the functional relationship between two quantities by analyzing a graph (e.g., where the function is increasing or decreasing, linear or nonlinear). Sketch a graph that exhibits the qualitative features of a function that has been described verbally. Connections: 6-8.WHST.2a-f; ET08-S1C2-01; SC08-S5C205 Mathematical Practices 8.MP.2. Reason abstractly and quantitatively. 8.MP.3. Construct viable arguments and critique the reasoning of others. When scuba divers come back to the surface of the water, they need to be careful not to ascend too quickly. Divers should not come to the surface more quickly than a rate of 0.75 ft per second. If the divers start at a depth of 100 feet, the equation d = 0.75t – 100 shows the relationship between the time of the ascent in seconds (t) and the distance from the surface in feet (d). o Will they be at the surface in 5 minutes? How long will it take the divers to surface from their dive? Make a table of values showing several times and the corresponding distance of the divers from the surface. Explain what your table shows. How do the values in the table relate to your equation? Examples & Explanations Example: The graph below shows a student’s trip to school. This student walks to his friend’s house and, together, they ride a bus to school. The bus stops once before arriving at school. Describe how each part A-E of the graph relates to the story. 8.MP.4. Model with mathematics. 8.MP.5. Use appropriate tools strategically. 8.MP.6. Attend to precision. 8.MP.7. Look for and make use of structure. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 26 Additional Domain Information – Functions (F) Key Vocabulary (BOLD means most important) Domain Function Input Linear function Nonlinear function Output Point Slope Form Range Slope Intercept Form Slope/Rate of Change Vertical line test X Intercept Y Intercept Example Resources Books HOLT (Chapter 3.3-3.5,13.4) Math In Context (Ups and Downs, Algebra Rules!, Patterns and Figures) CMP2 (7th grade: Moving Straight Ahead) Algebra 1 book (1.6-1.7, 4.2-4.3,5.2) Technology http://www.jonathanwray.com/resources.html#algebra Provides several useful interactive sites to use with students on functions. http://www.geogebra.org/cms/ Create graphs or show examples of functions. http://www.learningwave.com/lwonline/algebra_section2/slope3.html This site explains how to find slope, gives simple examples, and provides problem solving examples. http://www.nctm.org/standards/content.aspx?id=26883 Student can modify a rate of change and learn how modifications in that rate affect the linear graph displaying accumulation with real life scenarios. Exemplary Lessons http://www.curriki.org/xwiki/bin/view/Coll_MSP2/AlgebraicThinkingABasicSkill After giving several links on background information for teachers, this resource guide provides several links to exemplary resources under the subtitles: Working with algebraic expressions, Solving equations, Understanding graphs, From patterns to relations to functions. http://www.realworldmath.org/Real_World_Math/Lunar_Sports.html This lesson combines math and science on a field trip that takes place on the moon. Students will analyze the effects of low gravity environments on physical activity, measure and record various types of physical activity, and write a function and apply a factor of 6 to data measurements. http://www.shodor.org/interactivate/lessons/ImpossibleGraphs/ This lesson is devoted to impossible graphs. Users of the module can learn to distinguish between possible and impossible graphs of functions, and to learn why some graphs are impossible. These activities together give a brief lesson that can be completed in as little as 30 minutes class-time, depending on how many teams need to share their ideas. The discovery process takes about 15 minutes, and each presentation about 5 minutes. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 27 http://www.shodor.org/interactivate/lessons/GraphsAndFunctions/ This lesson is designed to introduce students to graphing functions. These activities can be done individually or in teams of as many as four students. Allow for 2-3 hours of class time for the entire lesson if all portions are done in class. Alignment 1: 8.F.4 from http://www.illustrativemathematics.org/standards/k8 Construct a function to model a linear relationship between two quantities. Determine the rate of change and initial value of the function from a description of a relationship or from two (x,y) values, including reading these from a table or from a graph. Interpret the rate of change and initial value of a linear function in terms of the situation it models, and in terms of its graph or a table of values. Assessments All assessments for this domain must focus on assessing the degree, to which seventh grade students can, within the parameters specified in the 3 standards included in this domain, define, evaluate, and compare functions and use functions to model relationships between quantities. Both formative and summative assessments are vital components of effective mathematics curricula. Formative assessments, (e.g., pre-assessments, daily checks for understanding, discussions of strategies students use to solve problems, etc.) assist in instructional planning and implementation; summative assessments (e.g., unit assessments, quarterly benchmarks, etc.) inform learner growth related to important mathematics concepts. All district-adopted resources contain multiple assessment tools and include online resources that can be used for the purposes delineated above. PARCC also will provide two end of the year summative assessments. The first, a performance-based assessment, will focus on applying skills, concepts, and understandings to solve multi-step problems requiring abstract reasoning, precision, perseverance, and strategic use of tools. The performance measure will be administered as close to the end of the school year as possible. The second, an end of the year machine-scorable summative assessment will be administered after approximately 90% of the school year. These assessments are to begin during the SY 2014-2015. Common Student Misconceptions: Students commonly mislabel a table as a function, because they mix up the inputs and outputs. For example, students think that when they see two of the same outputs, that the table cannot be a function. This is not true. A table is not a function if it has the same input with two different outputs. Students often view a graph as a literal picture of a situation (iconic representation). When asked what a graph like the one pictured above might represent, a student might answer that it shows someone traveling up a hill, down the other side, due east along a flat road, and then down a hill. Conversely, if asked to show graphically a runner’s trip around an oval track, a student might draw a picture of the track (an oval). Students may misunderstand what the graph represents in context. For example, a line moving up or down on a graph does not necessarily mean that a person is moving up or down. Students need to make sure they are reading the graph in terms of the labels on the x and y axis. For example a flat line on a distance vs. time graph means that the person has stopped moving, whereas on a speed vs. time graph a straight line indicates they are not speeding up or slowing down; they are staying at a constant speed. Students reverse coordinates when representing the slope. Students should have several opportunities to remember that the formula for slope is rise Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 28 over run. Students have difficulty with slope because they are taught to graph points left or right and then up or down and the slope is backwards. One way to help students with this misconception is to draw your steps above the line instead of below the line, showing up or down first then left or right. Students commonly think that vertical lines are linear functions. This is because they are told that if it is a straight line, then it is linear function. But a vertical line will not pass the vertical line test to show that it is a function. Some students will mix up x- and y-axes on the coordinate plane, or mix up the ordered pairs. When emphasizing that the first value is plotted on the horizontal axes (usually x, with positive to the right) and the second is the vertical axis (usually called y, with positive up), point out that this is merely a convention. It could have been otherwise, but it is very useful for people to agree on a standard customary practice. Some students do not pay attention to the scale on a graph, assuming that the scale units are always “one”. When making axes for a graph, some students do not use equal intervals to create the scale. Students often confuse a recursive rule with an explicit formula for a function. For example, after identifying that a linear function shows an increase of 2 in the values of the output for every change of 1 in the input, some students will represent the table with the equation y = x + 2, instead of realizing that this means y = 2x + b. When tables are constructed with increasing consecutive integers for input values, then the distinction between the recursive and explicit formulas is about whether you are reasoning vertically or horizontally in the table. Both types of reasoning—and both types of formulas—are important for developing proficiency with functions. Students mistakenly believe that linear functions (with a constant rate of change) are the only type of functions. Students need to be exposed to other functions, such as quadratics and exponential functions. Students commonly do not recognize a constant rate of change when entries in a table are absent. When input values are not increasing consecutive integers (e.g., when the input values are decreasing, when some integers are skipped, or when some input values are not integers), some students have more difficulty identifying the pattern and calculating the slope. It is important that all students have experience with such tables, to be sure that they do not over generalize from the easier examples. Students frequently attempt to “solve” expressions. Many students add “ = 0 ” to an expression they were asked to simplify, so that they can solve it. Students need to understand the difference between an expression and an equation. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 29 Geometry (G) (3 Clusters) 8.G Understand congruence and similarity using physical models, transparencies, or geometry software. (Cluster 1Standards 1, 2, 3, 4, and 5) Essential Concepts Essential Questions Translating a point, line, line segment or angle does not change any attributes of that object, it will just move the object to a new location. When a point is reflected across a line that reflected point stays the same distance from the line of reflection as the original point. When a line segment or angle is rotated, reflected or translated, the length of that line segment and measure of the angle will not change. A sequence of rotations, reflections, and/or translations to a twodimensional figure will create a congruent two-dimensional figure. An image is the figure created by doing a transformation on the preimage (or original object). A dilation of a two-dimensional figure will create an image that is a similar figure to the original by a multiplicative relationship. A translated, reflected or rotated two-dimensional figure will create an image that is a congruent figure to the original. Similar figures are produced by doing a sequence of rotations, reflections, translations AND dilations. The sequence of transformation must include dilation in order to produce a similar figure. Similar figures are figures that have the same angles and proportional side lengths. Parallel lines cut by a transversal will create pairs of angles that are either congruent or supplementary. The relationships between the angles made by parallel lines cut by a transversal can be used to informally prove that the interior angles of a triangle will add up to 180o. 8.G.1 Standard 8.G.1 Verify experimentally the properties of rotations, reflections, and translations: a. Lines are taken to lines, and line segments to line segments of the same length. b. Angles are taken to angles of the same Mathematical Practices 8.MP.4. Model with mathematics. 8.MP.5. Use appropriate tools strategically. What effect do translating, rotating and reflecting have on a point? Line? Line segment? Angle? Why does doing a sequence of rotations, reflections, and translations create congruent figures? Why does a dilation create a similar figure as opposed to a congruent figure? What effect does a dilation, translation, rotation and reflection have on a two-dimensional figure on the coordinate plane? How do you determine if two figures are similar? How do determine if a pair of angles created by parallel lines cut by a transversal will be congruent or supplementary? Describe how parallel lines cut by a transversal can be used to prove that the interior angles of a triangle will add up to 180o. Examples & Explanations Students need multiple opportunities to explore the transformation of figures so that they can appreciate that points stay the same distance apart and lines stay at the same angle after they have been rotated, reflected, and/or translated. Students are not expected to work formally with properties of dilations until high school. 8.MP.6. Attend to Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 30 measure. Parallel lines are taken to parallel lines. precision. 8.MP.7. Look for and make use of structure. 8.MP.8. Look for and express regularity in repeated reasoning. 8.G.2 Standard 8.G.2 Understand that a twodimensional figure is congruent to another if the second can be obtained from the first by a sequence of rotations, reflections, and translations; given two congruent figures, describe a sequence that exhibits the congruence between them. Connections: 6-8.WHST.2b,f; ET08-S6C1-03 Mathematical Practices 8.MP.2. Reason abstractly and quantitatively. Examples & Explanations Examples: Is Figure A congruent to Figure A’? Explain how you know. 8.MP.4. Model with mathematics. 8.MP.6. Attend to precision. 8.MP.7. Look for and make use of structure. Describe the sequence of transformations that results in the transformation of Figure A to Figure A’. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 31 8.G Understand congruence and similarity using physical models, transparencies, or geometry software. (Cluster 1Standards 1, 2, 3, 4, and 5) 8.G.3 Standard 8.G.3 Mathematical Examples & Explanations Describe the effect of A dilation is a transformation that moves each point along a ray emanating from a fixed center, and Practices dilations, translations, rotations, and reflections on two-dimensional figures using coordinates. Connections: 6-8.WHST.2b,f; ET08-S6C1-03 8.MP.3. Construct viable arguments and critique the reasoning of others. multiplies distances from the center by a common scale factor. In dilated figures, the dilated figure is similar to its pre-image. Translation: A translation is a transformation of an object that moves the object so that every point of the object moves in the same direction as well as the same distance. In a translation, the translated object is congruent to its pre-image. 8.MP.4. Model with mathematics. 8.MP.5. Use appropriate tools strategically. Example: has been translated 7 units to the right and 3 units up. To get from A (1,5) to A’ (8,8), move A 7 units to the right (from x = 1 to x = 8) and 3 units up (from y = 5 to y = 8). Points B + C also move in the same direction (7 units to the right and 3 units up). 8.MP.6. Attend to precision. 8.MP.7. Look for and make use of structure. Reflection: A reflection is a transformation that flips an object across a line of reflection (in a coordinate grid the line of reflection may be the x or y axis). In a reflection, the reflected object is congruent to its pre-image. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 32 When an object is reflected across the y axis, the reflected x coordinate is the opposite of the preimage x coordinate. Rotation: A rotated figure is a figure that has been turned about a fixed point. This is called the center of rotation. A figure can be rotated up to 360˚. Rotated figures are congruent to their preimage figures. Consider when DEF is rotated 180˚ clockwise about the origin. The coordinates of DEF are D(2,5), E(2,1), and F(8,1). When rotated 180˚, D' E ' F ' has new coordinates D’(-2,-5), E’(-2,-1) and F’(-8,-1). Each coordinate is the opposite of its pre-image. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 33 8.G Understand congruence and similarity using physical models, transparencies, or geometry software. (Cluster 1Standards 1, 2, 3, 4, and 5) 8.G.4 Standard 8.G.4 Mathematical Examples & Explanations Understand that a twoExamples: Practices dimensional figure is similar to another if the second can be obtained from the first by a sequence of rotations, reflections, translations, and dilations; given two similar two-dimensional figures, describe a sequence that exhibits the similarity between them. 8.MP.2. Reason abstractly and quantitatively. Connections: 8.EE.6; 68.WHST.2b,f; ET08-S6C1-03; ET08-S1C101 8.MP.6. Attend to precision. Is Figure A similar to Figure A’? Explain how you know. Describe the sequence of transformations that results in the transformation of Figure A to Figure A’. 8.MP.4. Model with mathematics. 8.MP.5. Use appropriate tools strategically. 8.MP.7. Look for and make use of structure. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 34 8.G Understand congruence and similarity using physical models, transparencies, or geometry software. (Cluster 1Standards 1, 2, 3, 4, and 5) 8.G.5 Standard 8.G.5 Mathematical Explanations & Examples Use informal arguments to Angle relationships that can be explored include but are not limited to: Practices establish facts about the angle sum and exterior angle of triangles, about the angles created when parallel lines are cut by a transversal, and the angle-angle criterion for similarity of triangles. For example, arrange three copies of the same triangle so that the sum of the three angles appears to form a line, and give an argument in terms of transversals why this is so. Connections: 6-8.WHST.2b,f; 6-8.WHST.1b; ET08-S6C103; ET08-S1C1-01; ET08S1C3-03 8.MP.3. Construct viable arguments and critique the reasoning of others. 8.MP.4. Model with mathematics. 8.MP.5. Use appropriate tools strategically. Same-side (consecutive) interior and same-side (consecutive) exterior angles are supplementary. Corresponding, Alternate interior angles and alternate exterior angles. Examples: Arrange three copies of the same triangle so that the sum of the three angles appears to form a line, and give an argument in terms of transversals why this is so. Students can informally prove relationships with transversals. Show that m 3 + m 4 + m 5 = 180˚ if l and m are parallel lines and t1 & t2 are transversals. 8.MP.6. Attend to precision. 1 + 2 + 3 = 180˚. Angle 1 and Angle 5 are congruent because they are corresponding angles ( 5 1 ). 1 can be substituted for 5 . 8.MP.7. Look for and make use of structure. 4 2 : because alternate interior angles are congruent. 4 can be substituted for 2 Therefore m 3 + m 4 + m 5 = 180˚ Students can informally conclude that the sum of a triangle is 180º (the angle-sum theorem) by Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 35 applying their understanding of lines and alternate interior angles. In the figure below, line x is parallel to line yz: Angle a is 35º because it alternates with the angle inside the triangle that measures 35º. Angle c is 80º because it alternates with the angle inside the triangle that measures 80º. Because lines have a measure of 180º, and angles a + b + c form a straight line, then angle b must be 65 º (180 – 35 + 80 = 65). Therefore, the sum of the angles of the triangle are 35º + 65 º + 80 º Examples: Write and solve an equation to find the measure of angle x. Write and solve an equation to find the measure of angle x. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 36 8.G Understand and apply the Pythagorean Theorem (Cluster 2- Standards 6, 7, and 8) Essential Concepts Essential Questions Pythagorean theorem states that for a right triangle the sum of the square of the two legs is equal to the square of the hypotenuse. (a2+b2 = c2) The converse of the Pythagorean theorem states that if the sum of the squares of the smaller sides in a triangle equals the square of the third side, then the triangle must be a right triangle. If a triangle is a right triangle, Pythagorean theorem can be used to find a missing side length or hypotenuse. Real world problems in both two and three dimensions that involve right triangles can be solved using Pythagorean theorem. The distance between two points on a coordinate plane can be found by drawing the vertical and horizontal lines from the points to create a right triangle and then applying the Pythagorean theorem. 8.G.6 Standard 8.G.6 Explain a proof of the Pythagorean Theorem and its converse. Connections: 6-8.WHST.2a-f; ET08-S1C2-01 What is a proof of the Pythagorean theorem? What is a proof of the converse of the Pythagorean theorem? How do you use Pythagorean theorem to find the missing side length or hypotenuse of a right triangle? What is an example of a real world problem that can be solved using Pythagorean theorem? Describe how you use Pythagorean theorem to solve the problem. What is an example of a real world problem that can be solved using the converse of Pythagorean theorem? Describe how you use Pythagorean theorem to solve the problem. How do you use Pythagorean theorem to find the distance between two points on a coordinate plane? Mathematical Practices Examples & Explanations 8.MP.3. Construct viable arguments and critique the reasoning of others. Pythagorean Theorem: Students should verify, using a model, that the sum of the squares of the legs is equal to the square of the hypotenuse in a right triangle. 8.MP.4. Model with mathematics. 8.MP.6. Attend to precision. 8.MP.7. Look for and make use of structure. Image from: myastrologybook.com Converse of Pythagorean Theorem: Students should also understand that if the sum of the squares of the 2 smaller legs of a triangle is equal to the square of the third leg, then the triangle is a right triangle Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 37 8.G Understand and apply the Pythagorean Theorem (Cluster 2- Standards 6, 7, and 8) 8.G.7 Standard 8.G.7 Mathematical Examples & Explanations Apply the Pythagorean Through authentic experiences and exploration, students should use the Pythagorean Theorem to Practices Theorem to determine unknown side lengths in right triangles in real-world and mathematical problems in two and three dimensions. Connections: 8.NS.2; ET08S2C2-01 8.MP.1. Make sense of problems and persevere in solving them. solve problems. Problems can include working in both two and three dimensions. Students should be familiar with the common Pythagorean triplets. 8.MP.2. Reason abstractly and quantitatively. 8.MP.4. Model with mathematics. 8.MP.5. Use appropriate tools strategically. Image from: akhnatonsjournal.org 8.MP.6. Attend to precision. 8.MP.7. Look for and make use of structure. 8.G.8 Standard 8.G.8 Apply the Pythagorean Theorem to find the distance between two points in a coordinate system. Connections: 8.NS.2; ET08S6C1-03 Mathematical Practices 8.MP.1. Make sense of problems and persevere in solving them. Examples & Explanations Example: Students will create a right triangle from the two points given (as shown in the diagram below) and then use the Pythagorean Theorem to find the distance between the two given points. 8.MP.2. Reason abstractly and quantitatively. 8.MP.4. Model with mathematics. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 38 8.MP.5. Use appropriate tools strategically. 8.MP.6. Attend to precision. 8.MP.7. Look for and make use of structure. 8.G Solve real-world and mathematical problems involving volume of cylinders, cones, and spheres (Cluster 3Standard 9) Essential Concepts Essential Questions 2 The volume of a cylinder is the area of the base multiplied the height Why is the volume of a cylinder V r h ? What does each part of 2 the formula represent in terms of the cylinder? (circle x height) that is V r h . The volume of the cone is 1/3 the volume of a cylinder. 1 2 r h r h or V 3 3 4 3 The volume of a sphere is V r 3 2 V How can you prove that the volume of a cone is 1/3 of the volume of a cylinder with the same radius and height? What are examples ofreal world problems that are solved by finding the volume of a three-dimensional figure such as a cone, cylinder or sphere? The formulas for finding the volume of three-dimensional figures are used to solve real world problems that involve filling three-dimensional figures. 8.G.9 Standard 8.G.9 Know the formulas for the volumes of cones, cylinders, and spheres and use them to solve real-world and mathematical problems. Connections: 6-8.RST.3; 68.RST.7; ET08-S2C2-01; ET08-S1C401 Mathematical Practices 8.MP.1. Make sense of problems and persevere in solving them. 8.MP.2. Reason abstractly and quantitatively. 8.MP.3. Construct viable arguments Tucson Unified School District Mathematics Curriculum Examples & Explanations Volume of a cylinder: V r h 2 1 2 r 2 h Volume of a Cone: V r h or V 3 3 4 3 Volume of a sphere is V r 3 Continued on next page Grade 8 Board Approved 03/27/2012 39 and critique the reasoning of others. Example: James wanted to plant pansies in his new planter. He wondered how much potting soil he should buy to fill it. Use the measurements in the diagram below to determine the planter’s volume. 8.MP.4. Model with mathematics. 8.MP.5. Use appropriate tools strategically. 8.MP.6. Attend to precision. 8.MP.7. Look for and make use of structure. 8.MP.8. Look for and express regularity in repeated reasoning. Additional Domain Information – Geometry (G) Key Vocabulary (BOLD means most important) Adjacent angles Alternate interior angles Cone Congruent Corresponding angles Cylinder Dilation Exterior angles Hypotenuse Interior angles Parallel Lines Perpendicular lines Prism Pythagorean Theorem Reflection Right angle Rotation Similar Skew lines Sphere Transformation Translation Transversal Triangle Sum Theorem Vertical angles Volume Example Resources Book HOLT (Chapter 7, 8.5-8.6,8.9,4.8, 5.5-5.6) Math In Context (Patterns and Symbols, It’s All the Same, Looking at Angle) CMP2 (8th grade: Looking or Pythagoras, Kaleidoscopes, Hubcaps and Mirrors, 7 th grade: Filling and Wrapping) Algebra 1 book (11.4) Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 40 Technology Geogebra.org An interactive geometry intended for teachers and students. Constructions can be made with points, vectors, segments, lines polygons, conic sections. Teachers and students can use GeoGebra to make conjectures and prove geometric theorems. http://www.mathwarehouse.com/solid-geometry/cylinder/formula-volume-of-cylinder.php# This site examines the properties of right circular cylinder with examples and practice problems http://www.calculatoredge.com/enggcalc/volume.html Online volume calculator http://www.brightstorm.com/math/geometry/ Free online geometry video lessons to help students with the formulas, terms and theorems related to triangles, polygons, circles, and other geometric shapes to improve their math problem solving skills. Titles include: Geometry Building Blocks; Reasoning, Diagonals, Angles, Parallel Lines; Constructions; Triangles; Transformations; Pythagorean Theorem; Volume; and Similarity Exemplary Lessons http://illuminations.nctm.org/LessonDetail.aspx?id=L791 In this lesson, students will use formulas they have explored for the volume of a cylinder and convert them into the same volume for rectangular prisms while trying to minimize the surface area. Various real world cylindrical objects will be measured and converted into a prism to hold the same volume. As an extension, students may design and create a rectangular prism container according to their dimensions to compare and contrast with the cylinder. http://www.pbs.org/teachers/connect/resources/4397/preview/ This lesson on Pythagorean theorem helps students understand the statement of the Pythagorean theorem, apply the Pythagorean theorem to solve for unknown sides of right triangles, and prove the Pythagorean theorem using the method developed by President James Garfield. http://www.pbs.org/teachers/connect/resources/4356/preview/ This lesson on transformations has students describe three types of symmetry, categorize symmetric figures based on type of symmetry, and create figures using different type of symmetry http://www.misterteacher.com/abc.html This lesson on transformations has students predict and describe positions and orientations of two-dimensional shapes after transformations such as reflections, rotations, and translations. It also includes Advanced Transformations where students predict and describe the results of translations, reflections, and rotations of objects in the coordinate plane. http://www.lessonplanspage.com/mathparallellinescutbytransversalproperties910-htm/ This lesson on parallel lines helps students understand and apply the angle theorems related to parallel lines to find given the measurement angles, provides practice the geometric proof technique to discover learning by comparing angle measurements and types of angles Assessments All assessments for this domain must focus on assessing the degree, to which seventh grade students can, within the parameters specified in the 3 standards included in this domain, Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 41 demonstrate an understanding of congruence and similarity using physical models, transparencies, or geometry software, demonstrate an understanding of and ability to apply the Pythagorean Theorem, and solve real-world and mathematical problems involving volume of cylinders, cones and spheres. Both formative and summative assessments are vital components of effective mathematics curricula. Formative assessments, (e.g., pre-assessments, daily checks for understanding, discussions of strategies students use to solve problems, etc.) assist in instructional planning and implementation; summative assessments (e.g., unit assessments, quarterly benchmarks, etc.) inform learner growth related to important mathematics concepts. All district-adopted resources contain multiple assessment tools and include online resources that can be used for the purposes delineated above. PARCC also will provide two end of the year summative assessments. The first, a performance-based assessment, will focus on applying skills, concepts, and understandings to solve multi-step problems requiring abstract reasoning, precision, perseverance, and strategic use of tools. The performance measure will be administered as close to the end of the school year as possible. The second, an end of the year machine-scorable summative assessment will be administered after approximately 90% of the school year. These assessments are to begin during the SY 2014-2015. Common Student Misconceptions Students tend to believe that similar figures will always face the same directions. For example, in the past students have been exposed to similar figures where the image has not been rotated at all. It is important the students be exposed to similar figures that are created by a sequence of transformations, including rotations, reflections, translations and dilations. For example, Students commonly think that the angles in similar figures are different. Students tend to think that because the side length get bigger or smaller, so do the angles. Students need opportunities to measure and compare angles in figures created by dilations. Students do not identify the variables as different legs on a right triangle: There is no connection made between the formula and the definition. Rather than saying a2 + b2 = c2, it is more useful for them to say (leg)2 + (leg)2 = (hypotenuse)2. Students commonly don not understand that the squared terms are the squares drawn off of each side of the right triangle. For example, a2 + b2 = c2 is in reference to the three squares that you draw off the legs and hypotenuse of the right triangle. It is not the sum of the lengths of the legs that will equal the length of the hypotenuse; it is the area of the squares off the legs that will sum to equal the area of the square off the hypotenuse. Students believe that the Pythagorean Theorem applies to all triangles. It is important to emphasize that Pythagorean Theorem includes the conditional statement that if you have a right triangle, then a2+b2 = c2. Students need opportunities to try Pythagorean theorem on all different types of triangles to determine which types of triangle the theorem holds true for. Students believe that volume is a number that results from substituting other numbers into a formula rather than a measure related to the Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 42 amount of space occupied. It is important to provide students opportunities for hands on experiences where students fill three dimensional objects. Students misinterpret coordinates. Students must understand that the x-axis is horizontal and the y-axis is vertical. Students must understand directions for positive and negative coordinates. Students need to understand that (x, y) is not the same as (y, x). Students assume the origin is always the center of rotation. The center of rotation should be carefully notated. Students should be exposed to multiple examples of rotations where the center of rotation is not at the origin. Students believe “x” and “y” are the only variables in ordered pairs. Use other variables, changing the variables of the axes accordingly. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 43 Statistics and Probability (SP) (1 Cluster) 8.SP Investigate patterns of association in bivariate data (Cluster 1- Standards 1, 2, 3, and 4) Essential Concepts Essential Questions Data that is collected using two variables is called bivariate data. Scatterplots and two-way frequency tables are used to show patterns of association and relationships between bivariate categorical data. Scatterplots can suggest a linear association/relationships. If a scatterplot suggests a linear relationship, then a line of best fit can be drawn and a linear equation can be created to model the relationship between the bivariate data. An equation of a line of best fit can be used to interpret and solve problems in the context of bivariate measurement data. 8.SP.1 Standard 8.SP.1 Construct and interpret scatterplots for bivariate measurement data to investigate patterns of association between two quantities. Describe patterns such as clustering, outliers, positive or negative association, linear association, and nonlinear association. Connections: 6-8.WHST.2b,f; ET08-S1C3-01; ET08-S1C302; ET08-S6C1-03; SS08-S4C1-01;SS08-S4C203; SS08-S4C1-05; SC08-S1C302; SC08-S1C3-03 Mathematical Practices 8.MP.2. Reason abstractly and quantitatively. 8.MP.4. Model with mathematics. 8.MP.5. Use appropriate tools strategically. 8.MP.6. Attend to precision. 8.MP.7. Look for and make use of structure. What are two ways to represent and/or display bivariate data and why would you use one as opposed to the other? What information will each of the two representations tell us about the bivariate data? How do you decide if a line of best fit is a good model to determine the relationship of bivariate data? What can a line of best fit tell us about bivariate data? Examples & Explanations Students create scatterplots and examine relationships between variables. They analyze scatterplots to determine positive and negative associations, the degree of association, and type of association. Students examine outliers to determine if data points are valid or represent a recording or measurement error. Students can use tools such as those at the National Center for Educational Statistics to create a graph or generate data sets. (http://nces.ed.gov/nceskids/createagraph/default.aspx) Examples: Data for 10 students’ Math and Science scores are provided in the chart. Describe the association between the Math and Science scores. Student 1 2 3 4 5 6 7 8 9 10 Math 64 50 85 34 56 24 72 63 42 93 Science 68 70 83 33 60 27 74 63 40 96 Continued on next page Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 44 Data for 10 students’ Math scores and the distance they live from school are provided in the table below. Describe the association between the Math scores and the distance they live from school. Student Math score Dist from school (miles) 1 64 2 50 3 85 4 34 5 56 6 24 7 72 8 63 9 42 10 93 0.5 1.8 1 2.3 3.4 0.2 2.5 1.6 0.8 2.5 Data from a local fast food restaurant is provided showing the number of staff members and the average time for filling an order are provided in the table below. Describe the association between the number of staff and the average time for filling an order. Number of staff Average time to fill order (seconds) 3 180 4 138 5 120 6 108 7 96 8 84 The chart below lists the life expectancy in years for people in the United States every five years from 1970 to 2005. What would you expect the life expectancy of a person in the United States to be in 2010, 2015, and 2020 based upon this data? Explain how you determined your values. Life Expectancy (in years) Date Tucson Unified School District Mathematics Curriculum 70.8 72.6 73.7 74.7 75.4 75.8 76.8 77.4 1970 1975 1980 1985 1990 1995 2000 2005 Grade 8 Board Approved 03/27/2012 45 8.SP Investigate patterns of association in bivariate data (Cluster 1- Standards 1, 2, 3, and 4) 8.SP.2 Standard 8.SP.2 Mathematical Examples & Explanations Know that straight lines are Examples: Practices widely used to model relationships between two quantitative variables. For scatterplots that suggest a linear association, informally fit a straight line, and informally assess the model fit by judging the closeness of the data points to the line. Connections: 8.EE.5; 8.F.3; ET08-S1C3-01; ET08-S6C103; SS08-S4C1-05; The capacity of the fuel tank in a car is 13.5 gallons. The table below shows the number of miles traveled and how many gallons of gas are left in the tank. Describe the relationship between the variables. If the data is linear, determine a line of best fit. Do you think the line represents a good fit for the data set? Why or why not? What is the average fuel efficiency of the car in miles per gallon? Miles Traveled 0 75 120 160 250 300 Gallons Used 0 2.3 4.5 5.7 9.7 10.7 8.MP.2. Reason abstractly and quantitatively. 8.MP.4. Model with mathematics. 8.MP.5. Use appropriate tools strategically. 8.MP.6. Attend to precision. 8.MP.7. Look for and make use of structure. 8.SP.3 Standard 8.SP.3 Use the equation of a linear model to solve problems in the context of bivariate measurement data, interpreting the slope and intercept. For example, in a linear model for a biology experiment, interpret a slope of 1.5 cm/hr as meaning that an additional hour of sunlight each day is associated with an additional 1.5 cm in mature plant height. Connections: 8.EE.5; 8.F.3; 8.F.4;ET08-S1C3-03; ET08S2C2-01; Mathematical Practices 8.MP.2. Reason abstractly and quantitatively. 8.MP.4. Model with mathematics. Examples & Explanations Examples: In a linear model for a biology experiment, interpret a slope of 1.5 cm/hr as meaning that an additional hour of sunlight each day is associated with an additional 1.5 cm in mature plant height. Given data from students’ math scores and absences, make a scatterplot. 8.MP.5. Use appropriate tools strategically. 8.MP.6. Attend to precision. 8.MP.7. Look for Continued on next page Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 46 and make use of structure. Draw a line of best fit, paying attention to the closeness of the data points on either side of the line. From the line of best fit, determine an approximate linear equation that models the given data (about y 25 x 95 ) 3 Students should recognize that 95 represents the y intercept and 25 represents the slope of 3 the line. Students can use this linear model to solve problems. For example, through substitution, they can use the equation to determine that a student with 4 absences should expect to receive a math score of about 62. They can then compare this value to their line. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 47 8.SP Investigate patterns of association in bivariate data (Cluster 1- Standards 1, 2, 3, and 4) 8.SP.4 Standard 8.SP.4 Mathematical Examples & Explanations Understand that patterns of Example: Practices association can also be seen in bivariate categorical data by displaying frequencies and relative frequencies in a twoway table. Construct and interpret a two-way table summarizing data on two categorical variables collected from the same subjects. Use relative frequencies calculated for rows or columns to describe possible association between the two variables. For example, collect data from students in your class on whether or not they have a curfew on school nights and whether or not they have assigned chores at home. Is there evidence that those who have a curfew also tend to have chores? 8.MP.2. Reason abstractly and quantitatively. Collect data from students in your class on whether or not they have a curfew on school nights and whether or not they have assigned chores at home. Is there evidence that those who have a curfew also tend to have chores? The table illustrates the results when 100 students were asked the survey questions: Do you have a curfew? and Do you have assigned chores? Is there evidence that those who have a curfew also tend to have chores? 8.MP.3. Construct viable arguments and critique the reasoning of others. 8.MP.4. Model with mathematics. 8.MP.5. Use appropriate tools strategically. 8.MP.6. Attend to precision. 8.MP.7. Look for and make use of structure. Connections: 6-8.WHST.2b,f; ET08-S1C1-01; ET08-S1C302; ET08-S1C3-03; SS08-S4C2-03; SS08-S4C105; SC08-S1C3-02 Solution: Of the students who answered that they had a curfew, 40 had chores and 10 did not. Of the students who answered they did not have a curfew, 10 had chores and 40 did not. From this sample, there appears to be a positive correlation between having a curfew and having chores. Additional Domain Information – Statistics and Probability (SP) Key Vocabulary (BOLD means most important) Bivariate Data Clustering Frequency Line of best fit Linear association Linear model Negative association Nonlinear association. Outliers Tucson Unified School District Mathematics Curriculum Positive association Relative Frequency Scatterplot Slope Two-way Table Grade 8 Board Approved 03/27/2012 48 Example Resources Book HOLT (9.7, 12.7) Math in Context (Insights into Data) CMP2( Samples and Population Investigation 4) Algebra 1 (5.6) Statistical Questions from the Classroom – NCTM This book presents eleven short discussions of some of the most frequently asked questions about statistics, questions that are consistently raised by statistics students and by classroom teachers alike. The authors offer teachers of statistics some quick insight and support in understanding these issues and explaining these ideas to their own students. Examples and visual representations of the ideas are included. Statistical Misconceptions – Schuyler W Huck This brief, inexpensive book is designed to help readers identify and then discard the major statistical misconceptions that have infiltrated the way they think about data. Technology http://nces.ed.gov/nceskids/createagraph/default.aspx Allows students to create their own graph in a bar, line, area, pie, and XY chart. http://cnx.org/content/m10949/latest/ Measures of central tendency, variability, and spread summarize a single variable by providing important information about its distribution. Often, more than one variable is collected on each individual. This site is a teacher resource for bivariate data including examples and vocabulary. Prerequisites are noted. http://www.northcanton.sparcc.org/~technology/excel/files/scatterplots.html As the user enters ordered pairs, the spreadsheet graphs a scatterplot, creates a line of best fit, and displays its equation (in linear or polynomial form). http://cwx.prenhall.com/bookbind/pubbooks/esm_sincich_pracstats_2/chapter2/custom1/deluxe-content.html This site explains how to make several types of tables, charts and graphs using Excel. A computer lab would be needed to make this a class project. Exemplary Lessons http://www.pbs.org/teachers/connect/resources/4103/preview/ This science-based lesson on data and scatterplots has students construct and evaluate graphs of the current sunspot cycle. This lesson plan includes a worksheet and extra resources. http://www.shodor.org/interactivate/lessons/UnivariateBivariateData/ This lesson is designed to introduce students to the differentiation between univariate and bivariate data. Students will gain experience determining what types of graphs and measures are appropriate for each type of data. This lesson is designed for students who are familiar with graphs and measures related to univariate data, even if they don't know the vocabulary term. http://ims.ode.state.oh.us/ODE/IMS/Lessons/Web_Content/CMA_LP_S05_BA_L09_I01_01.pdf. In this lesson, students create and Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 49 interpret various types of graphs from data gathered in class. In the analysis of the graphs, students classify data as univariate or bivariate and as quantitative or qualitative. Students also interpret frequency distributions based on spread, symmetry, skewness, clusters and outliers. http://illuminations.nctm.org/LessonDetail.aspx?ID=L298. Exploring Linear Data - Students model linear data in a variety of settings that range from car repair costs to sports to medicine. Students work to construct scatter- plots, interpret data points and trends, and investigate the notion of line of best fit. Assessments All assessments for this domain must focus on assessing the degree, to which seventh grade students can, within the parameters specified in the 3 standards included in this domain, investigate patterns of association in bivariate data. Both formative and summative assessments are vital components of effective mathematics curricula. Formative assessments, (e.g., pre-assessments, daily checks for understanding, discussions of strategies students use to solve problems, etc.) assist in instructional planning and implementation; summative assessments (e.g., unit assessments, quarterly benchmarks, etc.) inform learner growth related to important mathematics concepts. All district-adopted resources contain multiple assessment tools and include online resources that can be used for the purposes delineated above. PARCC also will provide two end of the year summative assessments. The first, a performance-based assessment, will focus on applying skills, concepts, and understandings to solve multi-step problems requiring abstract reasoning, precision, perseverance, and strategic use of tools. The performance measure will be administered as close to the end of the school year as possible. The second, an end of the year machine-scorable summative assessment will be administered after approximately 90% of the school year. These assessments are to begin during the SY 2014-2015. Common Student Misconceptions Students commonly try to connect all the points plotted on a scatter plot. This comes from their experience with linear functions and creating line graphs. Be sure to explain that these are discrete points and may not have data in between, therefore they cannot be connected the same way certain linear functions can be. Students believe that correlation between two variables automatically implies that one causes the other. Students should recognize bivariate data as two separate sets of data that can be represented in one display. They need to understand that correlation does not mean causation. Students may believe bivariate data is only displayed in scatter plots. Cluster 8.SP.4 provides the opportunity to display bivariate, categorical data in a table. Students assume the line of best fit must connect all data in a singular line. Because students are informally drawing lines of best fit, the lines will vary slightly. To obtain the exact line of best fit, students would use technology to find the line of regression. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 50 Students tend to try to find the line that has the most points on it. When students are trying to find lines of best fit, they need understand that you are also looking for the line with the closest number of points above and below the line as well as the number of points on the line. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 51 COMPARATIVE ANALYSIS: GRADE 8 MATHEMATICS PLANNING FOR CONTENT SHIFTS 2010 STANDARD 8.NS.1 Know that numbers that are not rational are called irrational. Understand informally that every number has a decimal expansion; for rational numbers show that the decimal expansion repeats eventually, and convert a decimal expansion which repeats eventually into a rational number. 8.NS.2 Use rational approximations of irrational numbers to compare the size of irrational numbers, locate them approximately on a number line diagram, and estimate the value of expressions (e.g., 2). For example, by truncating the decimal expansion of √2, show that √2 is between 1and 2, then between 1.4 and 1.5, and explain how to continue on to get better approximations. 2008 PO M08-S1C1-02 Classify real numbers as rational or irrational. 8.EE.1 Know and apply the properties of integer exponents to generate equivalent numerical expressions. For example, 323– 5 = 3–3 = 1/ 3 = 1/ 3 27. M08-S1C2-05 Simplify numerical expressions using the order of operations that include grouping symbols, square roots, cube roots, absolute values, and positive exponents. (positive exponents only) 8.EE.2 Use square root and cube root symbols to represent solutions to equations of the form x2 = p and x3 = p, where p is a positive rational number. Evaluate square roots of small perfect squares and cube roots of small perfect cubes. Know that √2 is irrational. 8.EE.3 Use numbers expressed in the form of a single digit times an integer PLAN M08-S1C1-03 Model the relationship between the subsets of the real number system. M06-S1C3-01 Use benchmarks as meaningful points of comparison for rational numbers. M07-S1C3-01 Estimate and apply benchmark numbers for rational number and common irrational numbers. M07-S1C3-03 Estimate square roots of numbers less than 1000 by locating them between two consecutive whole numbers. M08-S1C3-02 Estimate the location of rational and common irrational numbers on a number line. MHS-S1C2-01 Solve word problems involving absolute value, powers, roots, and scientific notation. MHS-S1C2-03 Calculate powers and roots of rational and irrational numbers. M06-S1C1-06 Express the inverse relationships between exponents and roots for perfect squares and cubes. M08-S1C1-02 Classify real numbers as rational or irrational. M07-S1C2-04 Represent and interpret numbers using scientific notation (positive exponents only). Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 52 2010 STANDARD power of 10 to estimate very large or very small quantities, and to express how many times as much one is than the other. For example, estimate the population of the United States as 3108 and the population of the world as 7109, and determine that the world population is more than 20 times larger. 8.EE.4 Perform operations with numbers expressed in scientific notation, including problems where both decimal and scientific notation are used. Use scientific notation and choose units of appropriate size for measurements of very large or very small quantities (e.g., use millimeters per year for seafloor spreading). Interpret scientific notation that has been generated by technology. 8.EE.5 Graph proportional relationships, interpreting the unit rate as the slope of the graph. Compare two different proportional relationships represented in different ways. For example, compare a distance-time graph to a distance-time equation to determine which of two moving objects has greater speed. 2008 PO M08-S1C2-04 Convert standard notation to scientific notation and vice versa (include positive and negative exponents). 8.EE.6 Use similar triangles to explain why the slope m is the same between any two distinct points on a non-vertical line in the coordinate plane; derive the equation y = mx for a line through the origin and the M08-S3C3-04 Translate between different representations of linear equations using symbols, graphs, tables, or written descriptions. M08-S3C4-01 Interpret the relationship between a linear equation and its graph, identifying and PLAN M08-S1C2-04 Convert standard notation to scientific notation and vice versa (include positive and negative exponents). MHS-S1C2-04 Compute using scientific notation. M08-S3C2-01 Sketch and interpret a graph that models a given context; describe a context that is modeled by a given graph. M08-S3C2-05 Demonstrate that proportional relationships are linear using equations, graphs, or tables. M08-S3C3-04 Translate between different representations of linear equations using symbols, graphs, tables, or written descriptions. M08-S3C4-01 Interpret the relationship between a linear equation and its graph, identifying and computing slope and intercepts. (missing comparison of 2 different graphs and/or equations) M08-S5C2-12 Make, validate, and justify conclusions and generalizations about linear relationships. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 53 2010 STANDARD equation y = mx + b for a line intercepting the vertical axis at b. 2008 PO computing slope and intercepts. (does not specifically address similar triangles) M08-S5C2-12 Make, validate, and justify conclusions and generalizations about linear relationships. PLAN 8.EE.7 Solve linear equations in one variable. a. Give examples of linear equations in one variable with one solution, infinitely many solutions, or no solutions. Show which of these possibilities is the case by successively transforming the given equation into simpler forms, until an equivalent equation of the form x = a, a = a, or a = b results (where a and b are different numbers). b. Solve linear equations with rational number coefficients, including equations whose solutions require expanding expressions using the distributive property and collecting like terms. 8.EE.8 Analyze and solve pairs of simultaneous linear equations. a. Understand that solutions to a system of two linear equations in two variables correspond to points of intersection of their graphs, because points of intersection satisfy both equations simultaneously. 8.EE.8 b. Solve systems of two linear equations in two variables algebraically, and estimate solutions by graphing the M07-S3C3-05 Create and solve two-step equations that can be solved using inverse operations with rational numbers. M08-S3C3-01 Write or identify algebraic expressions, equations, or inequalities that represent a situation. M07-S3C3-03 Solve multi-step equations using inverse properties with rational numbers. M07-S3C3-05 Create and solve two-step equations that can be solved using inverse operations with rational numbers. M08-S3C3-03 Analyze situations, simplify, and solve problems involving linear equations and inequalities using the properties of the real number system. MHS-S3C2-05 Recognize and solve problems that can be modeled using a system of two equations in two variables. M08-S1C3-01 Make estimates appropriate to a given situation. MHS-S3C3-07 Solve systems of two linear equations in two variables. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 54 2010 STANDARD equations. Solve simple cases by inspection. For example, 3x + 2y = 5 and 3x + 2y = 6 have no solution because 3x + 2y cannot simultaneously be 5 and 6. c. Solve real-world and mathematical problems leading to two linear equations in two variables. For example, given coordinates for two pairs of points, determine whether the line through the first pair of points intersects the line through the second pair. 8.F.1 Understand that a function is a rule that assigns to each input exactly one output. The graph of a function is the set of ordered pairs consisting of an input and the corresponding output. (Function notation is not required in Grade 8.) 8.F.2 Compare properties of two functions each represented in a different way (algebraically, graphically, numerically in tables, or by verbal descriptions). For example, given a linear function represented by a table of values and a linear function represented by an algebraic expression, determine which function has the greater rate of change. 8.F.3 Interpret the equation y = mx + b as defining a linear function, whose graph is a straight line; give examples of functions that are not linear. For example, the function A = s2 giving the area of a square as a function of its side length is not linear because its graph contains the points (1,1), (2,4) and (3,9), which are not on a straight line. 8.F.4 Construct a function to model a linear relationship between two quantities. 2008 PO MHS-S4C3-07 Determine the solution to a system of linear equations in two variables from the graphs of the equations. PLAN MHS-S3C2-05 Recognize and solve problems that can be modeled using a system of two equations in two variables. MHS-S3C3-07 Solve systems of two linear equations in two variables. M08-S3C2-02 Determine if a relationship represented by a graph or table is a function. * M08-S3C2-04 Identify functions as linear or nonlinear and contrast distinguishing properties of functions using equations, graphs, or tables. M08-S5C2-12 Make, validate, and justify conclusions and generalizations about linear relationships. M07-S3C4-01 Use graphs and tables to model and analyze change. (analysis of change) Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 55 2010 STANDARD Determine the rate of change and initial value of the function from a description of a relationship or from two (x, y) values, including reading these from a table or from a graph. Interpret the rate of change and initial value of a linear function in terms of the situation it models, and in terms of its graph or a table of values. 8.F.5 Describe qualitatively the functional relationship between two quantities by analyzing a graph (e.g., where the function is increasing or decreasing, linear or nonlinear). Sketch a graph that exhibits the qualitative features of a function that has been described verbally. 8.G.1 Verify experimentally the properties of rotations, reflections, and translations: 2008 PO M08-S3C1-01 Recognize, describe, create, and analyze numerical and geometric sequences using tables, graphs, words, or symbols; make conjectures about these sequences. M08-S3C2-03 Write the rule for a simple function using algebraic notation. (writing the rule) M08-S3C2-04 Identify functions as linear or nonlinear and contrast distinguishing properties of functions using equations, graphs, or tables. (properties of functions) M08-S3C3-04 Translate between different representations of linear equations using symbols, graphs, tables, or written descriptions. (different forms – equation/graphs) M08-S3C4-01 Interpret the relationship between a linear equation and its graph, identifying and computing slope and intercepts. (slope and rate of change) M08-S5C2-12 Make, validate, and justify conclusions and generalizations about linear relationships. M08-S3C2-01 Sketch and interpret a graph that models a given context; describe a context that is modeled by a given graph. M08-S3C2-04 Identify functions as linear or nonlinear and contrast distinguishing properties of functions using equations, graphs, or tables. PLAN M07-S4C2-01 Model the result of a double transformation (translations or reflections) of a 2dimensional figure on a coordinate plane using all four quadrants. M08-S4C2-01 Model the result of rotations in multiples of 45 degrees of a 2-dimensional figure about the origin. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 56 2010 STANDARD a. b. c. Lines are taken to lines, and line segments to line segments of the same length. Angles are taken to angles of the same measure. 2008 PO M08-S4C2-02 Describe the transformations that create a given tessellation. Aligned P.O.s do not specifically address line segments, angles, parallel lines. Rotations, reflections and translations of figures are specifically addressed. PLAN Parallel lines are taken to parallel lines. 8.G.2 Understand that a two-dimensional figure is congruent to another if the second can be obtained from the first by a sequence of rotations, reflections, and translations; given two congruent figures, describe a sequence that exhibits the congruence between them. M07-S4C1-05 Identify corresponding parts of congruent figures. M07-S4C2-01 Model the result of a double transformation (translations or reflections) of a 2dimensional figure on a coordinate plane using all four quadrants. M08-S4C2-01 Model the result of rotations in multiples of 45 degrees of a 2-dimensional figure about the origin. M08-S4C2-02 Describe the transformations that create a given tessellation. M06-S4C2-01 Identify a simple translation or reflection and model its effect on a 2-dimensional figure on a coordinate plane using all four quadrants. 8.G.3 Describe the effect of dilations, translations, rotations, and reflections on two-dimensional figures using coordinates. M06-S4C2-01 Identify a simple translation or reflection and model its effect on a 2-dimensional figure on a coordinate plane using all four quadrants. M07-S4C2-01 Model the result of a double Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 57 2010 STANDARD 2008 PO transformation (translations or reflections) of a 2dimensional figure on a coordinate plane using all four quadrants. M07-S4C2-01 Model the result of rotations in multiples of 45 degrees of a 2-dimensional figure about the origin. MHS-S4C2-01 Determine whether a transformation of a 2-dimensional figure on a coordinate plane represents a translation, reflection, rotation, or dilation and whether congruence is preserved. MHS-S4C2-02 Determine the new coordinates of a point when a single transformation is performed on a 2-dimensional figure. MHS-S4C2-03 Sketch and describe the properties of a 2-dimensional figure that is the result of two or more transformations. MHS-S4C2-04 Determine the effects of a single transformation on linear or area measurements of a 2dimensional figure 8.G.4 Understand that a two-dimensional figure is similar to another if the second can be obtained from the first by a sequence of rotations, reflections, translations, and dilations; given two similar two-dimensional figures, describe a sequence that exhibits the similarity between them. M07-S4C2-01 Model the result of a double transformation (translations or reflections) of a 2dimensional figure on a coordinate plane using all four quadrants. M08-S4C1-03 Use proportional reasoning to determine congruence and similarity of triangles. M08-S4C2-01 Model the result of rotations in multiples of 45 degrees of a 2-dimensional figure about the origin. M08-S4C4-02 Solve geometric problems using ratios and proportions. PLAN MHS-S4C2-01 Determine whether a transformation of a 2-dimensional figure on a coordinate plane represents a translation, reflection, rotation, or dilation and whether congruence is preserved. MHS-S4C2-02 Determine the new coordinates of a point when a single transformation is performed on a 2-dimensional figure. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 58 2010 STANDARD 2008 PO MHS-S4C2-03 Sketch and describe the properties of a 2-dimensional figure that is the result of two or more transformations. MHS-S4C2-04 Determine the effects of a single transformation on linear or area measurements of a 2dimensional figure. 8.G.5 Use informal arguments to establish facts about the angle sum and exterior angle of triangles, about the angles created when parallel lines are cut by a transversal, and the angle-angle criterion for similarity of triangles. For example, arrange three copies of the same triangle so that the sum of the three angles appears to form a line, and give an argument in terms of transversals why this is so. M05-S4C1-02 Solve problems by understanding and applying the property that the sum of the interior angles of a triangle is 180˚. M07-S4C1-02 Analyze and determine relationships between angles created by parallel lines cut by a transversal. M08-S4C1-03 Use proportional reasoning to determine congruence and similarity of triangles. 8.G.6 Explain a proof of the Pythagorean Theorem and its converse. M08-S5C2-11 Identify simple valid arguments using if… then statements. M08-S5C2-13 Verify the Pythagorean Theorem using a valid argument. (does not address converse) M08-S4C1-04 Use the Pythagorean Theorem to solve problems (does not address 3D). 8.G.7 Apply the Pythagorean Theorem to determine unknown side lengths in right triangles in real-world and mathematical problems in two and three dimensions. 8.G.8 Apply the Pythagorean Theorem to find the distance between two points in a coordinate system. 8.G.9 Know the formulas for the volumes of cones, cylinders, and spheres and use them to solve real-world and mathematical problems. PLAN M08-S4C3-02 Use the Pythagorean Theorem to find the distance between two points in the coordinate plane. M08-S5C2-13 Verify the Pythagorean Theorem using a valid argument. M08-S4C4-03 Calculate the surface area and volume of rectangular prisms, right triangular prisms, and cylinders. MHS-S4C4-05 Calculate the surface area and volume of 3-dimensional figures and solve for missing measures. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 59 2010 STANDARD 8.SP.1 Construct and interpret scatter plots for bivariate measurement data to investigate patterns of association between two quantities. Describe patterns such as clustering, outliers, positive or negative association, linear association, and nonlinear association. 2008 PO M07-S2C1-01 Solve problems by selecting, constructing, and interpreting displays of data including multi-line graphs and scatterplots. M07-S2C1-02 Interpret trends in a data set, estimate values for missing data, and predict values for points beyond the range of the data set. M07-S2C1-03 Identify outliers and determine their effect on mean, median, mode, and range. M08-S2C1-01 Solve problems by selecting, constructing, interpreting, and calculating with displays of data, including box and whisker plots and scatterplots. 8.SP.2 Know that straight lines are widely used to model relationships between two quantitative variables. For scatter plots that suggest a linear association, informally fit a straight line, and informally assess the model fit by judging the closeness of the data points to the line. 8.SP.3 Use the equation of a linear model to solve problems in the context of bivariate measurement data, interpreting the slope and intercept. For example, in a linear model for a biology experiment, interpret a slope of 1.5 cm/hr as meaning that an additional hour of sunlight each day is associated with an additional 1.5 cm in mature plant height. M08-S2C1-01 Solve problems by selecting, constructing, interpreting, and calculating with displays of data, including box and whisker plots and scatterplots. PLAN M08-S3C3-01 Write or identify algebraic expressions, equations, or inequalities that represent a situation. M08-S3C3-04 Translate between different representations of linear equations using symbols, graphs, tables, or written descriptions. M08-S3C4-01 Interpret the relationship between a linear equation and its graph, identifying and computing slope and intercepts. M08-S5C2-12 Make, validate, and justify conclusions and generalizations about linear relationships. MHS-S2C1-03 Display data, including paired data, as lists, tables, matrices, and plots with or without technology; make predictions and observations about patterns or departures from patterns. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 60 2010 STANDARD 8.SP.4 Understand that patterns of association can also be seen in bivariate categorical data by displaying frequencies and relative frequencies in a two-way table. Construct and interpret a two-way table summarizing data on two categorical variables collected from the same subjects. Use relative frequencies calculated for rows or columns to describe possible association between the two variables. For example, collect data from students in your class on whether or not they have a curfew on school nights and whether or not they have assigned chores at home. Is there evidence that those who have a curfew also tend to have chores? 2008 PO M08-S2C1-02 Make inferences by comparing the same summary statistic for two or more data sets. 8.MP.1 Make sense of problems and persevere in solving them. M08-S5C2-01 Analyze a problem situation to determine the question(s) to be answered. PLAN MHS-S2C1-08 Design simple experiments or investigations and collect data to answer questions. M08-S5C2-02 Analyze and compare mathematical strategies for efficient problem solving; select and use one or more strategies to solve a problem. M08-S5C2-03 Identify relevant, missing, and extraneous information related to the solution to a problem. M08-S5C2-04 Represent a problem situation using multiple representations, describe the process used to solve the problem, and verify the reasonableness of the solution. M08-S5C2-05 Apply a previously used problemsolving strategy in a new context. M08-S5C2-06 Communicate the answer(s) to the question(s) in a problem using appropriate representations, including symbols and informal and formal mathematical language. M08-S5C2-07 Isolate and organize mathematical Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 61 2010 STANDARD 8.MP.2 Reason abstractly and quantitatively. 8.MP.3 Construct viable arguments and critique the reasoning of others. 8.MP.4 Model with mathematics. 2008 PO information taken from symbols, diagrams, and graphs to make inferences, draw conclusions, and justify reasoning. M08-S5C2-08 Describe when to use proportional reasoning to solve a problem. M08-S5C2-09 Make and test conjectures based on information collected from explorations and experiments. M08-S5C2-07 Isolate and organize mathematical information taken from symbols, diagrams, and graphs to make inferences, draw conclusions, and justify reasoning. M08-S5C2-08 Describe when to use proportional reasoning to solve a problem. PLAN M08-S5C2-04 Represent a problem situation using multiple representations, describe the process used to solve the problem, and verify the reasonableness of the solution. M08-S5C2-07 Isolate and organize mathematical information taken from symbols, diagrams, and graphs to make inferences, draw conclusions, and justify reasoning. M08-S5C2-09 Make and test conjectures based on information collected from explorations and experiments. M08-S5C2-02 Analyze and compare mathematical strategies for efficient problem solving; select and use one or more strategies to solve a problem. M08-S5C2-04 Represent a problem situation using multiple representations, describe the process used to solve the problem, and verify the reasonableness of the solution. M08-S5C2-05 Apply a previously used problemsolving strategy in a new context. M08-S5C2-06 Communicate the answer(s) to the question(s) in a problem using appropriate representations, including symbols and informal and Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 62 2010 STANDARD 8.MP.5 Use appropriate tools strategically. 8.MP.6 Attend to precision. 8.MP.7 Look for and make use of structure. 8.MP.8 Look for and express regularity in repeated reasoning. MOVEMENT MOVED TO GRADE 6 2008 PO formal mathematical language. M08-S5C2-07 Isolate and organize mathematical information taken from symbols, diagrams, and graphs to make inferences, draw conclusions, and justify reasoning. M08-S5C2-08 Describe when to use proportional reasoning to solve a problem. M08-S5C2-02 Analyze and compare mathematical strategies for efficient problem solving; select and use one or more strategies to solve a problem. M08-S5C2-09 Make and test conjectures based on information collected from explorations and experiments. M08-S5C2-06 Communicate the answer(s) to the question(s) in a problem using appropriate representations, including symbols and informal and formal mathematical language. PLAN M08-S5C2-07 Isolate and organize mathematical information taken from symbols, diagrams, and graphs to make inferences, draw conclusions, and justify reasoning. M08-S5C2-09 Make and test conjectures based on information collected from explorations and experiments. M08-S5C2-04 Represent a problem situation using multiple representations, describe the process used to solve the problem, and verify the reasonableness of the solution. 2008 PO M08-S1C1-01 Compare and order real numbers PLAN including very large and small integers, and decimals and fractions close to zero. MOVED TO GRADE 7 M08-S1C1-04 Model and solve problems Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 63 involving absolute values. MOVED TO GRADE 6 M08-S1C2-01 Solve problems with factors, multiples, divisibility or remainders, prime numbers, and composite numbers. MOVED TO GRADE 5 M08-S1C2-02 Describe the effect of multiplying and dividing a rational number by a number less than zero, a number between zero and one, one, and a number greater than one. MOVED TO GRADE 7 M08-S1C2-03 Solve problems involving percent increase, percent decrease, and simple interest rates. MOVED TO GRADE 7 M08-S2C1-03 Describe how summary statistics relate to the shape of the distribution. M08-S2C1-04 Determine whether information is represented effectively and appropriately given a graph or a set of data by identifying sources of bias and compare and contrast the effectiveness of different representations of data. M08-S2C1-05 Evaluate the design of an experiment. REMOVED MOVED TO GRADE 7 MOVED TO GRADE 7 MOVED TO GRADE 7 MOVED TO GRADE 7 REMOVED M08-S2C2-01 Determine theoretical and experimental conditional probabilities in compound probability experiments. M08-S2C2-02 Interpret probabilities within a given context and compare the outcome of an experiment to predictions made prior to performing the experiment. M08-S2C2-03 Use all possible outcomes (sample space) to determine the probability of dependent and independent events. M08-S2C3-01 Represent, analyze, and solve counting problems with or without ordering and Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 64 repetitions. REMOVED REMOVED MOVED TO GRADE 6 MOVED TO GRADE 6 REDISTRIBUTED TO GRADE 6 AND 7 MOVED TO HIGH SCHOOL MOVED TO GRADE 7 REMOVED MOVED TO HIGH SCHOOL REMOVED MOVED TO HIGH SCHOOL REMOVED M08-S2C3-02 Solve counting problems and represent counting principles algebraically including factorial notation. M08-S2C4-01 Use directed graphs to solve problems. M08-S3C3-02 Evaluate an expression containing variables by substituting rational numbers for the variables. M08-S3C3-05 Graph an inequality on a number line. M08-S3C4-02 Solve problems involving simple rates. M08-S4C1-01 Identify the attributes of circles: radius, diameter, chords, tangents, secants, inscribed angles, central angles, intercepted arcs, circumference, and area. M08-S4C1-02 Predict results of combining, subdividing, and changing shapes of plane figures and solids. M08-S4C2-03 Identify lines of symmetry in plane figures or classify types of symmetries of 2-dimensional figures. M08-S4C3-01 Make and test a conjecture about how to find the midpoint between any two points in the coordinate plane. M08-S4C4-01 Solve problems involving conversions within the same measurement system. M08-S5C1-01 Create an algorithm to solve problems involving indirect measurements, using proportional reasoning, dimensional analysis, and the concepts of density and rate. M08-S5C2-10 Solve logic problems Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 65 involving multiple variables, conditional statements, conjectures, and negation using words, charts, and pictures. Tucson Unified School District Mathematics Curriculum Grade 8 Board Approved 03/27/2012 66