← GCSE Mathematics

N4 Factors, multiples, primes, HCF/LCM, prime factorisation

Currently Exam-ready · last touched 2026-10-20

HCF from index form not yet used (14 Oct: evaluated both numbers and listed factors, 5 min on a 2-min guide). One example of lowest power of each shared prime; not urgent.

Every change

WhenChangeEvidenceSession
2026-10-20Secure → Exam-readyadjudicated paper #9 Q8: 2/2, why:retest, at the bar inside a timed section; secure since 7 Sep (37 days at the sitting) and HCF/LCM right cold again 19 Oct — spaced re-test rule, secure → examready.standalone
2026-10-20Secure → Secure19 Oct cold: HCF 12 and LCM 72 of 24 and 36 unaided via complete factor-pair lists; no prompt needed.session 119
2026-10-14Secure → Securepaper #9 Q8: 2/2, loss=none — evaluated A=600, B=180 and listed factors to reach 60; did not use the index form; 5 min on a 2-min guidesession 104
2026-09-07Developing → Secure7 Sep starter: HCF of 84 and 360 → 12, correct non-calculator. The uglier-numbers question the loose end called for, after 12/18 on 2 Sep. Two independent correct answers across separate sittings.session 7
2026-09-03Developing → Developing2 Sep starter: HCF 6 and LCM 36 of 12 and 18, correct. First independent HCF/LCM question asked since it was taught on 18 Aug. One question only, so no promotion.session 2

In papers

AttemptPaperQMarksNote
Exam practice — week 42 · maths, lit, cs — GCSE Mathematics sectionexam-skills #982/2B2 60. Method: evaluated A=600 and B=180 then listed factors to find the HCF — long way round (5 min on a 2-min guide) but correct. Did not use the prime factor form given. loss=none; technique note for later (use the index form).