Work out fact family instantly with clear inputs, formula shown and shareable results.
A fact family takes two numbers and their product (or sum) and writes all four related facts, using commutativity and the inverse operation. Children who see 6 x 7 and 42 / 7 as the same fact family halve the number of facts they need to memorise.
Multiplicative family
a x b = p, b x a = p, p / a = b, p / b = a
Additive family
a + b = s, b + a = s, s - a = b, s - b = a
a x b = p, b x a = p, p / a = b, p / b = a. A fact family takes two numbers and their product (or sum) and writes all four related facts, using commutativity and the inverse operation.
Children who see 6 x 7 and 42 / 7 as the same fact family halve the number of facts they need to memorise.
Enter first number, second number. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.