Fact family calculator
Type any two numbers and this free fact family calculator finds the third and writes every addition, subtraction, multiplication and division fact in the family.
This free fact family calculator builds the whole family from any two numbers. Choose addition and subtraction or multiplication and division, type two numbers, and the third number and all the facts appear.
Fact family calculator
Type any two numbers. The third number and all the facts appear.
- 6 + 9 = 15
- 9 + 6 = 15
- 15 − 6 = 9
- 15 − 9 = 6
How the fact family calculator works
- Pick add and subtract or multiply and divide.
- Type any two of the three boxes. Use whole numbers from 0 to 9999.
- The calculator fills in the third number, draws the triangle and lists every fact in the family.
- Type all three numbers to check whether they really form a fact family.
Examples to try
| Mode | Type | You get |
|---|---|---|
| Add and subtract | Part 7, Whole 15 | The other part is 8: 7 + 8 = 15, 8 + 7 = 15, 15 − 7 = 8, 15 − 8 = 7 |
| Add and subtract | Part 5, Part 5 | The whole is 10, and the family has two facts: 5 + 5 = 10 and 10 − 5 = 5 |
| Multiply and divide | Factor 6, Product 42 | The other factor is 7: 6 × 7 = 42, 7 × 6 = 42, 42 ÷ 6 = 7, 42 ÷ 7 = 6 |
| Multiply and divide | Factor 4, Factor 12 | The product is 48 with the family 4 × 12 = 48, 12 × 4 = 48, 48 ÷ 4 = 12, 48 ÷ 12 = 4 |
What if my numbers do not make a fact family?
The calculator tells you why. If the whole is smaller than a part, or if a product is not a multiple of the factor you typed, you will see a message explaining the problem. For example, 7 is not a multiple of 3, so 3 and 7 cannot be the factor and product of a whole-number family.
Make a worksheet instead
Want practice problems rather than one family at a time? Use the free fact family worksheet generator. It makes a new printable sheet every time, with an answer key.
Frequently asked questions
What is a fact family calculator?
It is a tool that takes two numbers and shows every addition, subtraction, multiplication or division fact that uses them with the third number. It is built to help children and parents see how fact families work.
Can it do negative numbers or decimals?
No. Fact families in elementary school use whole numbers, so the calculator accepts whole numbers from 0 to 9999.
Why are there sometimes only two facts?
When the two smaller numbers are equal, swapping them gives the same fact. The family 8, 8 and 16 has only 8 + 8 = 16 and 16 − 8 = 8.
New to this? Read what a fact family is first.