Understanding Related Subtraction Facts

This video tutorial introduces first graders to the concept of related subtraction facts, using part-part-whole mats as a visual aid. The teacher explains how numbers are related in math by using the same numbers in different subtraction sentences. Through examples with numbers five, seven, and nine, students learn to write related subtraction sentences by breaking down whole numbers into parts. The video emphasizes starting with the largest number and demonstrates how to create related subtraction facts using visual aids.

What does it mean when we say numbers are related in math?

• They are always even numbers.

• They use the same numbers in different operations.

• They are always odd numbers.

• They are part of the same family.

What is the purpose of a part-part-whole mat in subtraction?

• To add numbers together.

• To multiply numbers.

• To break a whole number into parts.

• To divide numbers.

If you start with 5 and take away 2, what is the remaining part?

• 1

• 2

• 3

• 4

Which of the following is a related subtraction fact for 5, 2, and 3?

• 5 - 3 = 2

• 5 - 4 = 1

• 5 - 2 = 4

• 5 - 1 = 3

What is the difference when you subtract 3 from 7?

• 2

• 3

• 4

• 5

Which subtraction sentence is related to 7 - 3 = 4?

• 7 - 4 = 3

• 7 - 2 = 5

• 7 - 6 = 1

• 7 - 5 = 2

Why must the whole number always come first in a subtraction sentence?

• Because it is an odd number.

• Because it is the smallest number.

• Because it is an even number.

• Because it is the largest number.

If you start with 9 and take away 5, what is the remaining part?

• 2

• 3

• 4

• 5

What is another related subtraction fact for 9, 5, and 4?

• 9 - 1 = 8

• 9 - 4 = 5

• 9 - 3 = 6

• 9 - 2 = 7

What is the first step in writing a subtraction sentence using a part-part-whole mat?

• Start with the smallest part.

• Start with the whole number.

• Start with the largest part.

• Start with any number.