Lesson 8 Subtract Your Way

    • Let’s subtract numbers within 1,000.

Warm-up Number Talk: Subtract Two-Digit Numbers

Find the value of each expression mentally.

Activity 1 Strategies to Subtract

Find the value of each difference in any way that makes sense to you. Explain or show your reasoning.

Activity 2 Base-ten Drawings

Problem 1

Jada and Han made drawings to show how they used base-ten blocks to find the value of . Their drawings are shown.

Jada’s drawing

Base ten diagram. 2 hundreds, 1 crossed out. 6 tens, 4 crossed out with arrow pointing to 10 ones with 3 crossed out and 2 ones crossed out.

Han’s drawing

Base ten diagram. 2 hundreds, 1 crossed out. 6 tens, 4 crossed out with arrow pointing to a ten with 3 crossed out and 2 ones crossed out.

How are their drawings alike? How are they different?

Problem 2

Here are three expressions, followed by three diagrams. Write each expression next to the diagram that represents it. Then, find the value of the expression.

  1. Base ten diagram. 2 hundreds with 1 crossed out, 6 tens with 4 crossed out with arrow pointing to 1 ten with 3 crossed out and two ones crossed out.
  2. Base ten diagram. 2 hundreds, one crossed out. 5 tens, 3 crossed out. Two ones, both crossed out.
  3. Base ten diagram. 2 hundreds crossed out with arrow pointing to 1 hundred with three tens crossed out and five tens crossed out. Two ones, 1 crossed out.

Practice Problem

Problem 1

Find the value of in a way that makes sense to you.