Factor Pairs
Free factors game: tap every pair that multiplies to the target — or spot that it is prime. Factoring practice for grades 3–5. No sign-up.
Grade 3–5 · Free · No sign-up
How to play & why it works
A target number appears — say 24 — with a set of candidate pairs. Tap every pair that really multiplies to the target (3 × 8, 4 × 6…), skip the impostors, and if the target is prime, say so. Check evaluates the whole selection at once.
Factoring is times tables turned inside out, and it is the skill fractions live or die on: simplifying 24/36 means seeing the shared factors instantly. Working with pairs (rather than lone factors) also plants the square-root boundary idea — factor pairs meet in the middle.
The systematic habit: walk up from 1. Does 1 work? 2? 3? Each hit gives you a pair for free from the other side. And the "prime" option keeps you honest — some targets have no pairs at all, and recognizing that quickly is its own valuable skill.
The free MathIt app continues into prime recognition, divisibility rules and fraction simplification, all under its adaptive difficulty engine.
Working in pairs rather than listing single factors is what makes factoring systematic. Start at 1, work upward, and stop once the pairs start repeating — for 24 that is 1 × 24, 2 × 12, 3 × 8, 4 × 6, and you are done. Children who hunt at random almost always miss one.
Primes are the instructive case. A number with no pair beyond 1 × itself is prime, and meeting that as a real outcome of a search teaches the definition far better than being told it. Factor pairs are also the machinery behind simplifying fractions and finding common denominators, which is where the skill pays off.
Skills you'll practice
Keep practicing
Frequently asked questions
What is a factor pair?
Two numbers that multiply to a target. For 24 the factor pairs are 1 × 24, 2 × 12, 3 × 8 and 4 × 6.
How do you find all the factor pairs of a number?
Test divisors from 1 upward, recording each pair as you find it, and stop when the two numbers in a pair meet or cross. Anything beyond that point repeats a pair you already have.
What makes a number prime?
It has exactly one factor pair: 1 and itself. 13 is prime; 12 is not, because 2 × 6 and 3 × 4 also work. Note that 1 itself is not prime.
Get the full game
Adaptive difficulty, daily streaks, and live 2–5 player math battles — free on iOS and Android.