Lesson 9 Compare Numbers on the Number Line

- Let’s compare numbers on the number line.

Warm-up Estimation Exploration: Hundreds

What number could this be?

Number line. Scale 300 to 400. Point plotted between 300 and 400.

Record an estimate that is:
too low
about right
too high
Record an estimate that is:
too low
about right
too high

Activity 1 Compare Comparisons

Each student compared 371 and 317, but represented their thinking in different ways.

Diego

Base-ten diagram. 3 hundreds. 7 tens. 1 one.

I see 3 hundreds for each number.
317 only has 1 ten, but 371 has 7 tens.
$371 > 317$

Clare

Each has 3 hundreds.
371 has 7 tens, but 317 only has 1 ten.
$317 < 371$

Jada

Number line. Scale 300 to 400 by tens. 11 evenly spaced tick marks. First tick mark, 300. Last tick mark, 400. Points plotted at 317 and 371.

I can see that 371 is farther to the right on my number line, so I know it is greater than 317.
$371 > 317$

What is the same and different about these students’ representations?

Discuss with a partner.
Try Jada’s way.
Estimate the location of 483 and 443 on the number line. Mark each number with a point. Label the point with the number it represents.
Use $>$ , $=$ , or $<$ to compare 483 and 443.

Activity 2 Compare in Different Ways

Problem 1

Locate and label 420 and 590 on the number line.
Use $<$ , $>$ , and $=$ to compare 420 and 590.

Problem 2

Estimate the location of 378 and 387 on the number line. Mark each number with a point. Label the point with the number it represents.
Use $<$ , $>$ , and $=$ to compare 378 and 387.

Problem 3

Diego and Jada compared 2 numbers. Use their work to figure out what numbers they compared. Then use $<$ , $>$ , and $=$ to compare the numbers.
Which representation was most helpful to compare the numbers? Why?

Practice Problem

Problem 1

Estimate the location of 247 and 274 on the number line. Mark each number with a point. Label the point with the number it represents.
Use $<$ , $>$ , or $=$ to compare 247 and 274. Explain your reasoning.