Name Class Date Review 25 _ Using Variables ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• MATERIALS: None OBJECTIVE: Using variables as a shorthand way of expressing relationships You often hear word phrases such as half as milch or three times as deep. These phrases descrihe mathematical relationships. You can translate word phrases like these into mathematical relationships called expressions. Translate the following word expressions into algebraic expressions. the sum of x and 15 x seven times x 7x Remember that "times" mean to multiply. + 15 Remember that "sum" means to add. Translale the following word sentence into an algebraic equation. The weight of the truck is two times the weight of the car. -- = The weight of the truck is two times the weight of the car. ~ v , " I II j I 2 • c = t v = =. .# =. -- 2c "g ~ ~ w j g Represenl the unknown amounts with ,,'ariables. The translation is complete. Check to make sure )'OU h3l'e Iranslated all parts of the equation. ~ £ Write an equal sign under the word ;!J. Whatever is written to the left of ;!)' belongs on the left side of the Whatever is written to the right of;s belongs on the right side of the Exercises Translate the following word expressions and sentences into algebraic expressions or equations. 1. a number increased by 5 2. 8 subtracted from a number 3. a number divided by () 4. 3 less than five times a number 5. A number multiplied by 12 is M. 6. 7 less than 7. 8 times a number x is 72. 8. A number divided by 3 is 18. II is 22. ............................................................................. 1EIaI Name Class Date Review 26 Exponents _ and Order of Operations ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• OBJECTIVE: Using the order of operations MATERIALS:'Ibree index cards or small pieces of paper Review the order of operations to help you with this activity. I. 2. 3. 4. Order of Operations Perform any operations inside grouping symbols. Simplify any term with exponents. Multiply and divide in order from left to right. Add and subtract in order from left to right. Write + on the first index card, - on the second card, and X on the third card. Shuffle the cards and place them face down on your desk. Randomly pick cards to fill in the blanks with operation signs. Once you have filled in the operation signs. simplify the expression. 0_(9_7)_8 oX (9- 7) + 8 oX 2 12 + 8 - + 8 20 Pick cards to fill in the blanks ,,"'ithoperation signs. Suhtract 7 from 9 inside the grouping s,)'mbols. Do multiplication and division first. Multipl,)' 6 b}'2, Do addition and subtraction last. Add 12 and 8 to get the answer, - The answer is 20, Exercises Randoml,)' pick cards to fill in the operation s,)'mhols of the follo,,"ing expressions. Simplif,)' the expressions. 1.7_5_1 2.(3_9)_4 3.8_2_(5_10) 4.(3_7_0)_1 Simplif}' each expression b,)'following the order of operations. 5. (5 . 3) - 18 6. 5 . (3 - 18) 7. 2 . (27 - 13 . 2) 8. 2.27-13'2 9. 18 7 (9 - 15 7 5) 11. 2 . 8 - 62 m 10. tH + 9 - 15 + 5 12. 2 . (8 - 62) . Name ~ Class Date Review 27 _ Exploring _ Real Numbers ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• OBJECTIVE: Classifying numbers MATERIALS: None Review the following chart which shows the different classifications of real numbers. Rational terminating or repeating decimals I Rea'i (r~ __ '-_~_,_8_,4_2 Integers Whole ... -3, -2, -1,0,1,2,3, ... 0,1,2,3, ... ~ "... Irrational infinite, nonrepeating decimals !!, Ii 3.767667666 Given the numbers ~ ~ i -4.4. j -If and 32, tcll which numbers 32 numbers Whole: 0,32 natural numbers Integers: 0, -9,32 whole numbers Rational: -4.4, Irrational: -~ Real: -4.4, 14 5' O. -9. 1 14,32 used to count and zero and their opposites integers and tenninating infinite. nonrepeating 14 5' 0, -9, 1 14, -N, 32 belong to each set. rational and irrational and nonrepeating decimals decimals numbers Exercises Name the -et(s) of numhe" ,,- 5, <> O. -9, It. Natural: 1, -5 < ~4. ... 9, Vs ViOO tu whkh each uumher halongs, 2, 35.99 3, 0 4, 41 8 6, -80 7 , 11 5 12 8, "3 11, 3.24 12, 3. 10, -v4 Give an example of each kind of numher. 13. irrational ~ number 14. whole number 15. negative integer 16. fractional rational number 17. rational decimal 18, natural number .............................................. iii Name Class Date _ Review 28 Adding Real Numbers ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• OBJECTIVE: Adding integers and decimals MATERIALS: None Review the following addition rules. • To add two numbers with thc same sign, add their absolute values. The sum has the same sign as the numbers. • To add two numbers with different signs, find the difference of their absolute values. The sum has the same sign as the numbcr with the greater absolute value. The following example shows you step by step how to add two numbers with different signs. -6 + 2 6- 2 - 4 -4 Find the difference of their absolute values. Suhtract. - Since -6 has the greater absolute ".aloe, the ans".'er takes the negative sign. Exercises Simplify. Be sure to check the sign of )'our answer. 1. -3 + (~4) 2. 12 + 5 3. ~5 + 8 4. ~8 + (~2) 5. ~2 + (~3) 6. 9 + (~12) 7. ~3 + 5 8. ~4 + 3 9. ~2.3 + (~1.5) 13. 1.3 + (~1.1) 10. 4.5 + 3.1 11. -5.1 + 2.8 12. 13.9 + 7.3 14. ~3.6 + (~6.7) 15. 1.4 + (~21.4) 16. -9.8 + 3.5 Evaluate each expression for a = 5 and b = ~4. 17. ~a + (~b) 18. -a + h 19. a + b 20. a + (~b) Evaluate each expression for h = 3.4. 21. 2.5 + h 22. ~2.5 + h 23. 2.5 + (~h) 24. ~2.5 + (~h) 25. h + 7.1 26. ~h + 7.1 27. h + (~7.1) 28. ~h + (~7.1) IEEJI . Name Class Date Review 29 _ Subtracting Real Numbers ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• OBJECTIVE: Subtracting integers and decimals MATERIALS: None Review the following subtraction rules. • To subtract a number, rewrite the problem to add the opposite of the number. • Follow the rules for addition of numbers. The following example shows you step by step how to subtract two numbers. 5 - 11 5+(-11) 11 - 5 - Rewrite the problem to add tbe opposite of the number. - Find the difference of their absolute values. 6 -6 Subtnu.1. - Since -11 has the greater absolute value, the answer takes the negath'e sign. Simplify. Be sure 10 check the sign of Jour answer. 1. 7 - 12 2. 6 - 9 3.4-(-5) 4.7-(-3) 5. -6 - 4 6. -7 - 2 7. -5 - (-4) 8. -3 - (-10) 10. 8.3 - 5.1 11. -7.8 - 6.6 12. -4.8 - 2.5 14. -4.6 - (-3) 15. -9.3 - (-8.1) 16. -9.9 - 3.8 19. a - (-b) 20. -a - (-b) 9. -3.1 - (-5.4) 13. 8.7 - 2.5 E".aluale each expression for a = -4 and b = 3. 17. a - b 18. -a - b 21. 3b - a 22. -Ibl 23. la - bl 26. [-~]- U] Sublracl. (Hint: Sublracl corresponding clemenls.) 25. [-30 -~]- [~~] 24. lal - 31bl .................................................................. m Name Class Date Review 30 _ Multiplying and Dividing RealNumbers ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• OBJECTIVE: Multiplying and dividing integers and decimals MATERIALS:A number cube Review the following multiplication and division rules. • The product or quotient of two positive numbers is always positive. • The product or quotient of two negative numbers is always positive. • The product or quolient of a positive and a negative number is always negative . ..ID!llI Roll the number cube to determine the signs of the numbers in the following example. If you roll an even number (2,4, or 6), write + in the blank to make the number positive. If you roll an odd number (1, 3, or 5), write a - in the blank to make the number negative. Decide what sign the answer will have before you calculate the answer. 56 + Roll the number cube to fill in the blanks. 7 -56 -:- (+7) - Suppose Jour first roll was a 3, so 56 is negath'e. Suppose )'our second roll was 6, so 7 is positive. Now that )'OU have the signs of the numhers., decide what the sign of the answer will be. Dividing a negatil'e number by a positive number results in a negative numher. • - 8 - The answer is -8. Roll the numher cuhe to determine the signs of the numbeN in the follow'iug exercises. Rememher to decide what sign the ans,",'er will have hefore )'OU calculate the answer. 1. 20. 3. 27 5. 120 -:- 7. 1.4 . 8 + 3 12 3 2. 3.2 . 4. 14 . 6. 45 + 9 8. 96 + 8 10 4 Simplif)' each expression. 9. 4(-2) 10. -6(12) 11. -2(-5) 12. -8(11) 13. (-7)' 14. -10(-5) IEIDI . Name ~~. __ ~.~ .. Class Date Review 31 The Distributive _ Property ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• OBJECTIVE: Using the Distributive Property MATERIALS: None You can compare the Distributive Property to distributing paper to the class. Just as you distribute a piece of paper to each person in the class, you distribute the number immediately outside the parentheses to each term inside the parentheses by multiplying. Simplify 3(2x ~ 3(2x 3(2x) 6x + 3) by using the Distributive Property. + 3) + 3(3) + 9 - Draw arrows to show that 3 is distributed to the 2x and to the 3. - Use the Distributive Propert)'. - Simplif:y. Simplify -(4x + 7) by using the Distributive Property. ~ ~ c ~ ~ r= o -1(4x + 7) - Rewrite usin~ the Multiplication Property of -I. ~ -1(4x + 7) - Draw arrows to show that -I is distributed to the 4x and to the 7. -1(4x) + (-1)(7) - Use the Distributiw Propert)'. -4x - 7 - Simplif):. Exercises Draw arrm\'"sto show the Distributh'c Proper1)'. Then simplify each expression. ~ ~ 1. 2(5x + 4) 2. %(I2x - X) 3. 4(7x - 3) I 4. 5(4 + 2x) 5. 6(5 - 3x) 6. 0.1(30x - 50) ~ 7. (2x - 4)3 8. (3x + 4)7 9. 8(x + y) " 10. -(4x + 3) 11. -(-2x + 1) 12. -(-6x 13. -(14x - 3) 14. -(-7x - 1) 15. -(3x + 4) - 3) .................................................................... m Name Class Date Review 32 _ Properties of Real Numbers ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• OBJEaIVE: Recognizing properties MATERIALS: None The properties of real numbers allow you to write equivalent expressions. The Commutative Properties of Addition and Multiplication allow you to add or to multiply two numbers in any order. a + h = +a h a.b=b'a 3+6=6+3 12 . 4 = 4 . 12 The Associative Properties of Addition and Multiplication allow you to regroup numbers. + (a + b) + c = a (1 + 3) + 6 = 1 (b + c) (a • b) . , = a . (b . ,) + (3 + 6) (1 • 3) • 6 = 1 . (3 . 6) The Distributive Property distributes multiplication over addition and subtraction. u(b + c) + 3(4 6) = ah + ue = (3 . 4) + a(b - e) = ab - ae (3 . 6) 5(9 - 3) = (5 • 9) - (5 • 3) Name the property that cach equation illustrates. 72+56=56+72 -- Commutative Property of Addition: The order of the addends is changed. 4(5 - 9) (4 . 5) - (4 . 9) -- Distributh'e Pro pert)': The 4 is distributed. (30 • 14) . 5 -- Associative Property of Multiplication: The numben; are regrouped. = 30 . (14 • 5) = Exercises Name the property that each equation illustrates. 1. (17 + 4) + 9 = 17 + (4 + 9) 2. 7(3 + 4) = (7 • 3) + (7 • 4) 3. 84. 26 = 26 . 84 4. (3 . 6) . 7 = 3 . (6 . 7) 5. 8(6 - 3) = (8 . 6) - (8 . 3) 6. 4.2 + 3.4 = 3.4 + 4.2 Write the number that makes each statement true. 7. 27 + 9. 9(8 - 5) = 12 + 27 = (_ • 8) - (_ 11. 3. (9 . 6) = (3 . 9) . _ 1E!3I .•.•..•.•.•. 8. (8 . 5) + 20) + 9 + (20 + 9) = _ 10. 8. 10 = 10 . 12. 7(6 + 4) = (_ ~••••••••••••••.•.•..•.•.•..•.•.•..•.•....•..•••..•.•.••••.••••.• . 6) + (_ . 4) Name Class Date Review 33 _ Graphing Data on the Coordinate Plane ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• OBJECTIVE: Identifying coordinates on the coordinate plane MATERIALS: Graph paper Coordinates give the location of a point. To locate a point (x, y) on a graph, start at the origin, (0,0). Move x units to the right or to the left along the x-axis and y units up or down along the y-axis. Give the coordinates of points A, B, C, and D. Point A is 2 units to the left of the origin and 3 units up. The coordinates of A are (- 2,3). y A B Point B is 2 units to the right of the origin and 2 units up. The coordinates of Bare (2,2). x C - - 0 Point Cis 4 units to the left of the origin and up. The coordinates of Care (-4,0). o units Point D is 1 unit to the left of the origin and 3 units down. The coordinates of Dare (-1, - 3). Exercises Name the coordinates of each point. 1. G y 2. H K ~ •• • 3. J J 4. K ~ ~ 0 5. L 6. 1"1 ~ 7. N 8. P 9. Q 10. R 1 1 1.11 G L x H 0 N 0 E < ~ 0 , ~ w 0 •~ ~ 0 Q Graph the points on the same coordinate plane. 11. S (3. -5) 12. T (0. 0) 13. U(-I. -2) 14. V(4.5) 15. W (0. 3) 16. Z (-5.0) p R g ....................................................... m Name Class Date --~------ Review 34 --------- Solving One-Step Equations ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• OBJECTIVE: Solving one-step equations MATERIALS: Tiles As you model an equation with tiles. ask yourself what operation has been performed on the variable_ With the tiles, perform the inverse operation on each side of the equation. Simplify by removing zero pairs. • D:r!IllI!m3 Model each equation with tiles and solve. 1. x +4 = 6 DDD DDD ~DD DD DDD"III ~DDI!lIiiI DDII" DDDIIIIII DD ~ x = - Model the equation with tiles. - Subtract 4 from each side of the equation. - Simplify b~'rernol-ing zero pairs. - Model the equation with tiles. 2 2. 3x = 9 ~~~ DDDDD DDDD I[DDDI[DDI [DDD)D Dh-ide each side into three identical groups. ~~~ - DDD Solve for x. ~ x = 3 Model each equation with tiles and solve. 1. x + 3 10 2.y-4=2 3. -6 ~ 3y 4. 2x ~ 6 5.y+l=4 6. 5y ~ 10 7. x - 5 = 4 8. 12 = = Solve. 10. 17 = -8 + x 13. 5.2 + II = 0.3 9. x 4x 11. -0.5 ~ * 14. 14 = x + 7 11I3I .•.•..•.•.•..•.••.•.•.••.•.•..•.•..•.•.•....•.••.•.•..•.•.•..•.•.••.•..•.•..• + 12.0.0 0 4 = 2 -"5a _ 15.6x~15 Name Class Date Review 35 _ Solving Two-Step Equations ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• MATERIALS: None OBJECTIVE: Solving two-step equations The order of operations tells you to do multiplication and division before you do addition and subtraction. However, when solving two-step equations, you must first do any addition or subtraction necessary to isolate the variable on one side of the equation. Start by asking yourself, "Has any adding or subtracting been done to the variable?" If the answer is yes, perform the inverse operation. Then repeal this step for multiplication and division, Write the steps and solve the equation. 3x+4=10 3x + - Think: Is an)' adding or suhtracting being done to the variahle? 4 is being added. What is the inverse of adding 4'! - Suhtract 4 from each side. 3x = 6 - Simplif:,... 3x = 6 - Think: Is any multipl)'ing or dividing being done to the variable? It is heing multiplied b)' 3. What is the inverse of multipl)'ing h)"3? 3x = Q 3 --.- Dil'ide each side b)' 3. - Simplif)'. 4 - 4 = 10 - 4 3 x = 2 l :E1 ~ Exercises Fill in the blanks to eomplete the steps and soh'e the equation. i - 5 = -8 1. , 6 5 + 5 = -8 + 5 ~ = -3 6 6( - 3) - Think: Is any adding or subtracting heing done to the variable? _____ is heing • What is the of suhtracting 57 _____ 510 side. Simplify. Think: Is any multipl)'ing or dil'iding heing done to the nriahle? It is being h)' 6. What is the innrse of b)' 6? Multipl)' each by _ Simplif)'. Solve eaeh equalion. 2. 3x - 4 = 8 3. t + 3 = 10 4.4y+5=-7 .............••••••••••••••••................................................ ~ Name ~ etass Date Review 36 Solving Multi-Step _ Equations ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• OBJECTIVE: Combining like terms MATERIALS: None Simplify 3a - 6x + 4 - 2d + 5x by combining like terms. • Ring each term that has the variable a. Draw a rectangle around each term that has the variable x, and a triangle around each constant term. @ 1- 188 ~ 6x Group the like terms by reordering the terms so that all matching shapcs arc together. @8 BI+ 18 5x Combine like terms by adding coefficients. ll-x+4 Exercises Draw circles, rectangles, and triangles to help you combine like terms and simplif)' each expression. 1. 3([ + 5 - x + 7.• - 2([ 3. 7b - b - x + 5 - 2x - 7b 2. 2x - 5 + 3a - 5x 4. -6m , + 3t + 4 - 4m - 2t 5. 2,+3s-5, 6. 4 - P - 2x 7. 3k -2x+6k+5 8. 3 9. 4a+3-2y-Sa-7+4y + lOa ~ + 3p - 7.• ~ ~ .go + 2a - 7x + 2.5 + 5x ~ + 4x 10. c-3+2x-6c 0 E ", Simplify cach expression. Q " 0 11. 2h+2- .• +4 13- !a-S-!a 14. 1.Sy - 1.5 15. 6a+3h-2([+4 16. c + D.5y + 0.5.::+ 1 ~ •• ~ ta+S-la-7 17. -8 + x - 2 + 3x 18. x 19. ~x + 5 - ~x - 4 20. lOy - 3x 1EZaI ~ w 12. -S - c -4+3c @ + y - z + 4x - 5y + 2z + 5 - 8 - 2y .