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1st Grade Math: What is a Fact Family?

The Fact Family: A Key Concept in 1st Grade Math

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1st grade math

Your child will learn about the fact family in 1st grade math.

Image courtesy of Amanda Morin

Your child probably has 1st grade math homework this year and may even ask you to help with it. One of the more common concepts taught in first grade math is the concept of a fact family (or fact families). If you've never heard of this, it's actually quite easy.

Helping With 1st Grade Math

A fact family is made up of three numbers. Just as in any family the members, or numbers, are related and there are always at least four math facts to be made with them. Take, for example, these members of a fact family: 6, 4, and 10.

The Fact Family Relationships

In the family 6, 4, and 10 they are related because you can add two of the numbers to get the last number.

  • 6 + 4 = 10

You can also switch the first two numbers, using the commutative property of addition, and still get the same answer.

  • 4 + 6 = 10

Fact Family Cousins

If addition is the direct relationship amongst these family members, then subtraction is the family cousin through the inverse property. Simply put, subtraction is the opposite of addition, but it's still related.  The problems still only use the three members of the family.

  • 10 - 4 = 6
  • 10 -6 = 4

Keeping Track of All Family Members

Once your child knows the relationships of the fact family members, it's easy to see who is missing at a quick glance. Solving addition and subtraction problems is then much easier and starts to become automatic. Take for example, this problem:

  • 6 + ____  =  10

Your child should quickly be able to recognize 4 as the missing family member.

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