Unit 3, Lesson 10
Subtraction Algorithms (Part 3)
Grade 3
Warm-up
What do you notice? What do you wonder?
Activity 1
Andre and Clare found the value of . How they started their work is shown.
Andre's algorithm
Clare's algorithm
- Complete both algorithms to find the difference.
- Andre and Clare started their subtraction in different ways. How did their way of starting affect the steps needed to find the difference?
Activity 2
Clare used an algorithm to find the value of .
Try using her algorithm to find the value of each difference.