Lesson 15 Decompose a Ten and a Hundred to Subtract
Let’s subtract within 1,000.
Warm-up Choral Count: Hundreds and Tens
Count back by 10, starting at 590.
What patterns do you see?
Activity 1 Elena’s Thinking
Elena’s thinking:
Step 1:
Step 2:
Step 3:
Use base-ten blocks or a base-ten diagram to show Elena’s steps.
Finish Elena’s work to find the value of
. What is another way you could use numbers or equations to show subtracting by place to find the value of
?
Activity 2 Walk About and Subtract
Find someone with a different number than you.
Find the difference between your numbers.
Show your thinking.
Trade cards and find a new partner.
Partner 1:
Partner 2:
Partner 3:
Practice Problem
Problem 1
Find the value of each difference. Show your thinking.