Fact families and basic addition and subtraction facts
This article explains how to use fact families to help children learn the basic addition and subtraction facts (with single-digit numbers), and also contains a complete example lesson with exercises and word problems about fact families where the sum is 13 or 14.
Sample pages (PDF)
Contents & Introduction
Trick with 9 and 8
Review: Completing the Next Whole Ten
Adding with 8
Number Rainbows - 11 and 12
Fact Families with 13
What is a fact family?
A fact family is a group of math facts using the same numbers. In the case of addition/subtraction, you use three numbers and get four facts. For example, you can form a fact family using the three numbers 10, 2, and 12: 10 + 2 = 12, 2 + 10 = 12, 12 − 10 = 2, and 12 − 2 = 10.
Where do we use fact families?
We can use fact families to reinforce or learn the connection between addition and subtraction, and to help children memorize the basic addition & subtraction facts. The two videos below explain several strategies for learning addition and subtraction facts, including number rainbows and fact families.
After the videos, there follows a complete lesson with many exercises and word problems about fact families with 13 and 14 (where the sum is 13 or 14), taken from my book Math Mammoth Add & Subtract 2-A.
A Lesson on Fact Families - sums with 13 and 14
1. Fill in. In each fact family, color the marbles so they match the numbers in it.
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Fact families with 13 |
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2. Connect with a line the problems that
are from the same fact family. You
don't need to
write the answers.
13 − 7 = 
5 + 11 − 3 = 8 + 12 − 3 = 7 + |
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11 − 4 =
11 − 8 = 5 + 12 − 5 = 6 + 9 + |
12 − 7 =
13 − 6 = 3 + 13 − 5 = 3 + 4 + |
3. Fill in. In each fact family, color the marbles so they match the numbers in it.
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Fact families with 14 |
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4. Subtract.
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a. 13 − 8 = ____ 14 − 6 = ____ |
b. 13 −
5 =
____ 13 − 4 = ____ |
c. 12 −
7 =
____ 13 − 7 = ____ |
d. 12 −
9 =
____ 14 − 9 = ____ |
5. Find the missing numbers.
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a. 9 +
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b. 6 +
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c. 6 +
=
12
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| d.
− 9
=
4
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e.
− 7
=
7 |
f.
− 9
=
3
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| g. 14 −
= 8
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h. 12 −
=
7
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i. 13 −
=
8
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6. Solve the word problems.
| a.
Ted arranged his toy cars in rows. The first row had
seven cars, the second had seven, and the third row had four. How many cars does Ted have? |
| b. If you have 14 strawberries and I have
eight,
how many more do you have? |
| c. Dad
has six cherries and Mom has five more than him. How many cherries does Mom have?
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| d. At first Mom had 20 apples to make a pie,
but she gave each of the four children one apple before she made the pie. How many apples did she have left for the pie? |
7. Figure out the patterns and continue them!
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| 40 |
48 |
56 |
64 | 72 | _____ | _____ | _____ | _____ | |||||||||||||||||||||||||
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| 17 | 21 | 25 | 29 | _____ | _____ | _____ | _____ | _____ | |||||||||||||||||||||||||
This lesson is taken from Maria Miller's book Math Mammoth Add & Subtract 2A, and posted at www.HomeschoolMath.net with permission from the author. Copyright © Maria Miller.
Math Mammoth Add & Subtract 2-A
A self-teaching worktext for 2nd grade that covers “easy” additions and subtractions within 0-100; such as 24 + 5 and 89 − 7, or adding or subtracting whole tens; memorizing the basic addition facts of single-digit numbers, and learning to use them with subtraction.
Download ($3.95). Also available as a printed copy.
