Lesson 14 Make Sense of Decimal Subtraction

    • Let’s subtract decimals.

Warm-up True or False: Decimal Differences

Decide if each statement is true or false. Be prepared to explain your reasoning.

Activity 1 The Difference

  1. Find the value of . Explain or show your reasoning.

  2. What questions do you have about subtracting decimals?

Activity 2 Introduce Target Numbers: Subtract Tenths or Hundredths

Directions:

  1. Play one round of Target Numbers.

    • Partner A:

      • Start at 2. Roll the number cube. Choose whether to subtract that number of tenths or hundredths from your starting number.

      • Write an equation to represent the difference. 

    • Take turns until you’ve played 6 rounds.

    • Each round, the difference from the previous equations becomes the starting number in the new equation.

    • The partner to get a difference closest to 1 without going under wins.

  2. Describe a move that you could have made differently to change the outcome of the game.

Practice Problem

Problem 1

  1. Which whole number is closest to? Explain or show your reasoning.

  2. Find the value of .