Multiples and factors
The first real number theory. A prime has exactly two distinct factors; the sieve is a process, not a poster. Students list factor pairs, find common factors and multiples, classify primes and composites to 100, and apply the divisibility tests for 2, 3, 4, 5, 6, 9, and 10. Everything about fractions later is GCF and LCM in disguise.
Specification · for a parent or teacher
- factors-multiples-intro
- Advanced Math 4 · Unit 3
- Numbers
- 2 of 4 — Grade 4–5. Two steps, or one idea in a story.
- 3 items
Students can
list factor pairs; find common factors and common multiples; classify primes and composites to 100; apply divisibility tests for 2, 3, 4, 5, 6, 9, 10.
Ready when
they can say why 91 is composite and find all factors of 36 in pairs.
Watch for
1 classified as prime; 15 called prime because it is odd; divisibility by 3 tested on the last digit.