Prime or Composite? is a free printable Grade 4 maths worksheet on classifying by factor count, aligned to Common Core standard 4.OA.B.4. It prints 12 questions with an answer key on its own sheet of paper, in 25 versions that each ask different questions, so no two pupils in the class work from the same page. Print it from the browser or download it as a PDF — no account, no email.
Set 1 of 25 · the same problems every time you open this link.
Next set4.OA.B.4
Write prime or composite.
LessonPrint · 4.OA.B.4 · Set 1 · free to copy for classroom use
Set 1. Prints on its own sheet.
It practises classifying by factor count — 12 questions for Grade 4, all on Common Core 4.OA.B.4: Find factors and multiples, and tell prime from composite numbers. The instruction to pupils is “Write prime or composite”, and the answer key follows on the next sheet.
CCSS.MATH.CONTENT.4.OA.B.4 — 4.OA.B.4, in the Operations & Algebraic Thinking domain for Grade 4. The published standard reads: “Find all factor pairs for a whole number in the range 1-100. Recognize that a whole number is a multiple of each of its factors. Determine whether a given whole number is prime or composite.” The worksheet assesses that standard rather than a paraphrase of it.
Prime or Composite? is written for Grade 4, typically ages 9-10. It is one of the sheets on 4.OA.B.4, so it suits any pupil working at that standard — including older pupils revisiting it and younger ones working ahead.
Yes. All 12 answers are generated from the same problems as the questions, so the key cannot drift out of step with the sheet. It starts on a fresh sheet of paper, after the questions, so it is not handed out with the class by accident.
25 — one per pupil, and all 25 ask different questions. Set 1 downloads the whole class as a single PDF. Every version is fixed to its own address, so a sheet printed today holds the same problems when you reopen it next week.
Yes. Prime or Composite?, its answer key and its 25 versions are free to print and photocopy for your own class, with no account, no email capture and no subscription at the download step. Please do not resell them or republish them as your own.
Find factors and multiples, and tell prime from composite numbers.
Last reviewed 2026-09-05. Aligned to 4.OA.B.4 of the Common Core State Standards for mathematics.