First Grade Math: What Are Fact Families?

The Fact Family: A Key Concept in First Grade Math

girl doing math homework
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Your child probably has first-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 First 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 among 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.

Building a Fact Family House

A fun way to show the relationships of a fact family is to place the numbers in a house. Draw a typical house with a square box topped with a triangle for the attic and roof.

Now in the attic triangle, place the three numbers that will be part of the family in three attic windows.

In this case, you'd place 4, 6, and 10 in the attic windows.

In the main part of the house, place four large windows that contain the four different math operations of the fact family. These would be two for addition and two for subtraction:

__ + __ = __

__ - __ = __

Now your child can place the numbers appropriately in the equations and practice moving in their fact families. You can end up creating a whole neighborhood, such as each of the numbers that add up to 10.

This method of showing the relationships can make math a little more fun and approachable by your first-grader. Fact families help kids understand the patterns in mathematics.

More Advanced Fact Family Worksheets and Apps

You can find other worksheets for fact families in many places online if you want different ones to use at home. Beyond addition and subtraction, you'll find multiplication and division fact families to use as your child advances to higher grades. There are apps and tablet games you can also find for fact family fun.

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