Log in
Sign up for FREE
arrow_back
Library

Unit 3 - Lesson 11 - Grade 3: Illustrative Mathematics

star
star
star
star
star
Last updated about 1 year ago
11 questions
Note from the author:
Lesson: Analyze Subtraction Algorithms
Cool Down: Subtraction Reflection
1
1
Grade 3 Unit 3
Lesson 11: Analyze Subtraction Algorithms
CC BY 2021 Illustrative Mathematics®
Grade 3 Unit 3
Lesson 11: Analyze Subtraction Algorithms
CC BY 2021 Illustrative Mathematics®

Number Talk: Subtract within 1,000 (Warm Up)

Find the value of each expression mentally.
1
1
1
1

Compare Two Subtraction Algorithms

The first steps of two algorithms are shown.

1
1
1

Use an Algorithm?

Noah wanted to find the value of 301 - 167 and wrote:


Elena said that we can’t subtract this way because we would need more ones to subtract 7 ones, but there’s a zero in the tens place of 301.
1
1
You’ve learned many ways to subtract large numbers, including strategies and algorithms.
Question 10
10.

What is your favorite way to subtract large numbers?

Question 11
11.

What’s a way that you would like to learn more about and use more?

Question 1
1.

400 - 200

Question 2
2.

450 - 200

Question 3
3.

450 - 205

Question 4
4.

450 - 215

Question 5
5.

How are the steps different?

Question 6
6.

Use Algorithm A to find the value of 824 - 541.

Question 7
7.

Use Algorithm B to find the value of 824 - 541.

Question 8
8.

Do you agree with Elena's statement? Explain your reasoning.

Question 9
9.

Show how you would use an algorithm (either Noah's or another algorithm) to find the difference between 301 and 167.