Lesson 13 Subtract Strategically
Let’s consider when to use algorithms and when to use other strategies to subtract.
Warm-up Number Talk: Threes
Find the value of each expression mentally.
Activity 1 How Would You Subtract?
Use a strategy or algorithm of your choice to find the value of each difference. Show your reasoning. Organize it so it can be followed by others.
Activity 2 Greatest Difference, Smallest Difference
Decide with your partner whether you will try to make the greatest difference or smallest difference.
Take turns spinning and recording a digit in the hundreds, tens, or ones place. Continue until your numbers are complete.
Find the difference.
Compare your values.
Write a comparison using >, <, or =.
Play again.
Practice Problem
Problem 1
Use a strategy or algorithm of your choice to find the value of each difference.