Math test
Free · Grades 5–6 · 4 sections · 19 questions
GCF and LCM test
Greatest common factor, least common multiple, and the word problems that tell them apart.
- Answer key on its own page
- Reopen this exact paper
- Letter & A4 ready
The answer key prints on a separate page.
What's on this test
GCF and LCM are easy to compute and easy to confuse, and the confusion is the thing worth testing. One goes down — the biggest number that divides both — and one goes up: the smallest number both divide into. A child who has learned two procedures without that distinction will produce a confident answer to the wrong question.
How the paper is put together
That is what the word problems are for. Tiling a floor with the largest possible square is a GCF question; two buses leaving at different intervals and meeting again is LCM. Nothing in the wording says which, and choosing correctly is the whole of what the unit taught.


