“Recognizing Integers”

“Recognizing Integers” September, 2011 7th Grade Math

Math Innovations – Page 67 • What do you notice about the number line below? • Brainstorm with your partners and be prepared to share one thing from your group.

How did you do? • Numbers to the right of 0 are positive • Numbers to the left of 0 are negative • Number line is symmetrical about 0 • Pairs of numbers are same distance from 0 • Extends infinitely • Numbers written below the line • Numbers written below tick mark, not above or below interval • Positive numbers do not have a sign Math Innovations – Page 67 • What you thought…

Math Innovations – Page 67 • Draw a number line and label the tick marks from -10 to 10. • Check that your number line is straight • The intervals are evenly spaced • The numbers are written under the line • The numbers line up with the tick marks, not the spaces. • If necessary, fix your number line to meet these rules. • Compare your number line to another student’s. How are your lines the same? How are they different? Explain.

How can you tell by looking at a number line which numbers are larger? • How far does the number line “actually” go in the positive direction? Negative direction? • Can you name the LARGEST number that we could put on a number line? What direction would it be in? • Can you name the smallest number that we could put on a number line? What direction would it be in?

Brainstorm with your partners what you believe are the three (3) most important things someone should know about the number line.

“Kiss My Math” • This is how Danica views integers. She calls them “mintegers”.

Math Innovations – Page 67 • Let’s label the number line with negative fractions and decimals. • Draw 3 number lines from -1 to 1. • Locate ½ and – ½ • Locate 2/3 and – 2/3 • Locate 5/8 and -5/8 • Remember…To label a number line, start with zero and move to the right (positive), then to the left (negative) • Symmetrical about 0

1st 2nd Block Things I need to know… • Positive Numbers – Numbers greater than 0 • Negative Numbers – Numbers less than 0

It’s Your Turn…Part I • I have some number lines created and I want you to practice locating both positive and negative numbers on a number line. • Side #1 (Lesson 2.1 Number Lines)

Things I need to know… • The further right on the number the _________ the value. • Example #1: Compare 32,000,000 and 6,000,000 * 32 million is farther right on the number line. * Therefore, 32 million is greater than 6 million • Example #2: Compare -10 and -2 * -2 is farther right on the number line. * Therefore, -2 is greater than -10

It’s Your Turn…Part II • I have some number lines created and I want you to practice locating both positive and negative numbers on a number line. • Side #2 (Lesson Guide 2.1A Negative Fractions and Decimals)

Math Innovations • We talk about signed numbers using their direction and magnitude. • Direction – Tells whether the number has a positive direction (to the right of 0) or a negative direction (to the left of 0) • Magnitude (AKA Absolute Value) – How far the number is from 0 on the number line. Absolute Value is shown as || • Examples: • Give the magnitude and direction of 18. • Give the magnitude and direction of -23. • Give the magnitude and direction of -4 ½. • Give the magnitude and direction of 6.785

It’s Your Turn…Part III • Give the magnitude and direction of each number below. • -7.3 • -12 • 6 ¼ • -0.8

It’s Your Turn…Part IV • Give the absolute value of each number below. • |-7.3| • |-12| • |6 ¼| • |-0.8| • | | f. | | How are your answers here similar to the magnitude you found on previous slide?

Homework: • “Recognizing Integers” practice problems

“Recognizing Integers”