# Lesson 1 Compare, Count on, and Count Back

• Let’s compare numbers and add or subtract.

## Warm-up Number Talk: Count Back

Find the value of each expression mentally.

## Problem 1

Tyler and Elena were asked to find the value of .
Their work is shown.

Tyler

Elena

What do you notice? What do you wonder?

## Problem 2

1. Locate and label 203 and 198 on the number line.

2. Compare using >, <, or =.

3. Find the value of . Show your thinking.

## Problem 3

1. Locate and label 673 and 680 on the number line.

2. Compare using >, <, or =.

3. Find the value of . Show your thinking.

## Problem 4

1. Locate and label 501 and 499 on the number line.

2. Find the value of . Show your thinking.

## Problem 5

Find the value of . Show your thinking.

## Problem 1

1. Fill in the missing numbers.

2. Does this number line show counting on by 10 or counting on by 100?

## Problem 2

1. Fill in the missing numbers.

2. Does this number line show counting on by 10 or counting on by 100?

## Problem 3

1. Fill in the missing numbers.

2. Does this number line show counting on by 10 or counting on by 100?

## Problem 4

1. Fill in the missing numbers to show counting on by 10.

739, 749, , 769,

2. Explain how you can tell your numbers show counting on by 10 and not counting on by 100.

## Problem 1

Find the value of each difference. Show your thinking.