Lesson 11 Different Ways to Add and Subtract

• Let’s add and subtract by using a ten.

Warm-up Number Talk: Use Tens

Find the value of each expression mentally.

Activity 1 Compare Methods

Diego and Tyler found the value of . Their work is shown.

Diego’s Method:

Tyler’s Method:

1. Use Diego’s method to find the value of .

2. Use Tyler’s method to find the value of .

Activity 2 More Methods

1. Partner A

• Find the value of .

• Find the value of .

2. Partner B

• Find the value of .

• Find the value of .

Problem 1

Find the value of in two different ways. Show your thinking on the number lines.

1. Method 1:

2. Method 2: