Addition & Subtraction Facts Generator

Print a fact family worksheet in seconds: each triangle shows three numbers, and children write the four addition and subtraction facts that belong to it. Free, with an answer key.

What is a fact triangle?

A fact triangle, or fact family triangle, shows three numbers that belong together: two parts and their total. For 4, 5 and 9 there are four facts: 4 + 5 = 9, 5 + 4 = 9, 9 - 4 = 5 and 9 - 5 = 4. The total sits at the top of the triangle and the two parts at the bottom corners.

Seeing the three numbers together helps children understand that subtraction is not a separate set of facts to memorise. It is the same fact family, read the other way. Once a child knows 4 + 5 = 9, they already know 9 - 5.

How to make the worksheet

Choose the number of triangles on the page: 6, 9 or 12. Six triangles is a calm first sheet, twelve is a full practice page.
Choose 1 or 2 digits for the two smaller numbers. One digit keeps the facts within 18, two digits makes larger fact families such as 35, 48 and 83.
Press Create and check the preview. Press Download PDF to save the sheet, or Print to send it straight to your printer. Press Create again whenever you want a fresh set: the numbers change, the layout stays the same.
Press Show answers to fill in all four facts under each triangle, and print that page as the answer key.

Which grade is it for?

1st grade: one digit, 6 triangles. Many children first meet fact families in 1st grade, and the small numbers let them check each fact with counters.

2nd grade: one digit for fluency, then two digits once children add and subtract two-digit numbers. Two-digit triangles are also a good way to practise checking subtraction with addition.

3rd grade: two digits, 12 triangles, as quick review.

Tips for using fact triangles

Cover one corner of the triangle with your thumb and ask which number is hidden. This turns the triangle into a quick flash card.
Ask your child to read each fact out loud as they write it. Saying 9 take away 4 is 5 helps the fact family stick.
Pair a fact triangle sheet with a subtraction worksheet. Children who get stuck on a subtraction problem can look for its fact family.

Using the sheets at home and in class

At home, cut the printed triangles apart and use them as flash cards: hold one up with a corner covered and ask for the hidden number. Keep the ones your child finds hard in a small pile and practise those more often. In class, fact triangles work well in pairs, with one child covering a number and the other answering. A 6-triangle sheet is also a quick exit ticket at the end of a lesson on fact families, and it shows at a glance who understands how addition and subtraction are linked.

What is on the printed page

Each triangle has the largest number at the top and the two smaller numbers in the bottom corners. Under it are four short equations with a blank to fill in. The page has a title, a name and date line, and enough space between triangles for young writers. It prints well in black and white.