Maria Bessler Math Lesson: Scientific Notation (5th Grade) MATERIALS: Copy of pre/post test on scientific notation (two copies per student) Astronomy Picture of the Day "Scale of the Universe-Interactive" http://apod.nasa.gov/apod/ap120312.html Teacher reference: http://www.chem.tamu.edu/class/fyp/mathrev/mr-scnot.html Website that converts numbers to scientific notation: http://www.mathsisfun.com/numbers/scientific-notation.html Website to practice and check scientific notation: http://janus.astro.umd.edu/cgibin/astro/scinote.pl Examples of scientific notation: http://mrsgrotheer.weebly.com/uploads/8/3/8/9/8389616/scientificnotationwks 4website.pdf ESSENTIAL QUESTIONS: Why do we use scientific notation? When is scientific notation helpful, and when is it unhelpful? KEY CONCEPTS: identifying the pattern found in scientific notation applying when to use scientific notation deductive reasoning and critical thinking OBJECTIVES: In this lesson, students will: SOL Computation and Estimation (Focus: Multistep Applications and Order of Operations) 5.5 The student will a) find the sum, difference, product, and quotient of two numbers expressed as decimals through thousandths (divisors with only one nonzero digit); and b) create and solve single-step and multistep practical problems involving decimals. SOL Computation and Estimation (Focus: Applications of Operations with Rational Numbers) 6.7 The student will solve single-step and multistep practical problems involving addition, subtraction, multiplication, and division of decimals. SOL Number and Number Sense (Focus: Proportional Reasoning ) 7.1 The student will a) investigate and describe the concept of negative exponents for powers of ten; b) determine scientific notation for numbers greater than zero; c) compare and order fractions, decimals, percents, and numbers written in scientific notation; convert large and small numbers between standard and scientific notation Vocabulary/Themes: scientific notation, integer, expression, equation, standard notation 1 Maria Bessler PROCEDURES: TEACHER NOTES: Introduction/Hook: What is a power of 10? What does is look like in real life? Visit the Astronomy Picture of the Day website, date March 12, to view the "Scale of the Universe" through the powers of 10: http://apod.nasa.gov/apod/ap120312.html Pre-test students on scientific notation prior to the lesson, and adjust content accordingly. Learning Activities: What did you notice about the items on the scale? [Ranged from very large to very small] What happened to the power of 10 in the corner of the screen as we zoomed in and out? [The exponent was negative for small items and positive for large items] Can you write out the number two billion, nine hundred million? Now, I would like you to write out the number seven octillion. (Hint: it has 27 zeros. ) Now let's put seven octillion into the calculator and add fifteen trillion to it! Is this a convenient way of writing these numbers? No! We can't fit these numbers into a calculator this way. There is a better method, a "shorthand", a way of taking notes on numbers: scientific notation, often used by scientists. We use the powers of ten to write a mathematical expression that represents the number. This works well for numbers that are very large or very small and take a long time to write out in standard form (also called standard notation). Two billion becomes 2.9 x 10^9 Seven octillion becomes 7 x 10^27 Fifteen trillion becomes 1.5 x 10^13 Scientific notation takes a very long number to write out, and simplifies it into two factors: an integer or decimal between 0 and 10 (positive or negative), and a power of 10. 2 Scientific notation-when a number is expressed as a product of a decimal/integer and a power of 10. Used when numbers are too large or too small to be written conveniently in decimal/ standard form. (2.3 x 10^4) Integer-a whole number (positive or negative) Expression-combination of symbols (5 x 4) Equation-math statement showing equality between two sets of expressions (5 x 4 = 20) Standard notation-when a number is expressed in standard form. (23000) Note: 10^0 = 1 Underlined part is called the significant part of the number. Maria Bessler Take students to the website: http://www.chem.tamu.edu/class/fyp/mathrev/mrscnot.html to view some examples of scientific notation. Have students identify that the pattern for converting numbers between standard and scientific notation. If a number in scientific notation has a negative exponent, it is a number less than zero and you need to move the decimal point to the left as many places as the number of the exponent. Example: 4.234 x 10^-3 = 0.004234 If a number in scientific notation has a positive exponent, it is a number greater than zero and you need to move the decimal point to the right as many places as the number of the exponent. Example: 7.293 x 10^6 = 7293000 Have students practice putting numbers into scientific notation, and converting them back to standard notation. Numbers close to zero can be put in scientific notation, but this takes longer than necessary. Scientific notation is most helpful when working with very large or very small numbers. Interest Center: Allow several students at a time to visit the APOD "Scale of the Universe" website via classroom computers to interact with the simulation and 'explore the universe.' Have them share their findings with the class. Grouping: Students will be grouped in a whole-class grouping for direct instruction on scientific notation since it is a new concept for all students, according to the pretest. Students will work and take notes in small groups of 3-6 at their working tables, and a 4 computers are available for students to explore the scientific notation-related websites shown to them in this lesson. Debriefing: Post-test on scientific notation (same as pre-test). Collect and review answers together as a class. 3 Examples: 3 = 3 x 10^0 528 = 5.28 x 10^2 0.009 = 9 x 10^-3 Maria Bessler Homework: (Optional) Look for very large or very small numbers in the newspaper, on the Internet, etc. and practice converting them to scientific notation. Differentiation for: ELL Twice-Exceptional Highly Gifted Differentiation: Choice: Resources: Products: Tiered questions/assignments: 4 Allow student to visit website http://janus.astro.umd.edu/cgibin/astro/scinote.pl to do practice problems and be able to check the work.