GCSE Maths Year 1 Week 2
- Sallyann Clark
- 16 hours ago
- 4 min read
Week 2: Factors, Multiples, Primes, HCF & LCM
Welcome back for Week 2!
Last week was all about arithmetic fluency; this week we build straight on top of that with factors, multiples, primes, and two ideas that trip a lot of people up the first time they meet them: the Highest Common Factor (HCF) and Lowest Common Multiple (LCM). Once these click, they'll quietly show up everywhere for the rest of the course, simplifying fractions, algebra, and ratio, so it's worth taking the time to get comfortable now.
Same shape as last week: warm-up, teach, practice (pick your level — Foundation, Intermediate or Higher), mark, exit ticket. Roughly 45 minutes a day, but treat the timings as a guide rather than a stopwatch; if you're in the middle of something and it's going well, finish it properly rather than cutting it off.
Monday — Factors & Multiples
What you're learning: The difference between a factor and a multiple (easy to mix up at first), and how to find all the factors or the first several multiples of a number confidently.
Warm-up (5 min): Topmarks — Hit the Button (times tables/division mode) — this recalls your multiplication and division work from Week 1, which spotting factors and multiples leans on directly.
Teach (10 min): Watch:
Quick way to keep the two straight: factors of a number divide into it exactly (the factors of 12 are 1, 2, 3, 4, 6, 12); multiples of a number are what you get when you multiply it by whole numbers (the multiples of 12 are 12, 24, 36, 48...). Factors are always smaller than or equal to the number; multiples go on forever.
Practice (20 min): Pick one path:
Foundation: Transum — Factors hub — start with the Times Square activity and any basic factor-spotting games.
Intermediate: Corbett Maths — Multiples, Factors & Primes Practice, the full page.
Higher: Corbett Practice (question 19-29) plus Transum — Factor Trees Challenge for a proper stretch.
Mark & fix: As before — check, correct, and note why for anything you got wrong.
Exit ticket: List all the factors of 36. How do you know you haven't missed any?
Tuesday — Prime Numbers & Prime Factorisation
What you're learning: What makes a number prime, and how to break any number down into a product of its prime factors using a factor tree.
Warm-up (5 min): Corbett Maths 5-a-day (GCSE) — general mixed recall of what you already know.
Teach (10 min): Watch:
Quick reminder: a prime number has exactly two factors — 1 and itself. 1 is not prime (it only has one factor). 2 is the only even prime number. Everything else even is automatically out.
Practice (20 min): Pick one path:
Foundation: Transum — Sieve of Eratosthenes / Pick the Primes.
Intermediate: Corbett Maths — Product of Primes/LCM/HCF Practice, the full page.
Higher: Corbett Textbook Exercise (Apply questions only) plus Transum — Factor Trees Challenge.
Mark & fix: As before.
Exit ticket: Write 60 as a product of its prime factors. Draw the factor tree you used.
Wednesday — Highest Common Factor (HCF)
What you're learning: How to find the largest number that divides exactly into two (or more) numbers, using either listing or prime factorisation, whichever method clicks better for you.
Warm-up (5 min): Topmarks — Pick the Primes — recall of yesterday's prime numbers, which the prime-factorisation method for HCF (below) leans on.
Teach (10 min): Watch:
Practice (20 min): Pick one path:
Foundation: Transum — HCF and LCM, Level 1-2 only.
Intermediate: Corbett Maths — LCM/HCF Practice and Transum — HCF and LCM, Levels 2-3.
Higher:Textbook Exercise and Transum — HCF and LCM, Level 3-4 (large numbers).
Mark & fix: As before.
Exit ticket: Find the HCF of 48 and 60. Show your method, not just the answer.
Thursday — Lowest Common Multiple (LCM)
What you're learning: How to find the smallest number that both of two given numbers divide into.
Warm-up (5 min): Topmarks — Multiples and Factors — the game has two modes; play the HCF mode only today, as recall of yesterday.
Teach (10 min): Watch:
Practice (20 min): Pick one path:
Foundation: Transum — HCF and LCM, Levels 2-3 only.
Intermediate: Corbett Textbook Exercise and Transum — HCF and LCM Levels 3-4.
Higher: Product of Primes worksheet and Transum — HCF and LCM, Levels 4–5 (three numbers).
Mark & fix: As before — HCF and LCM questions are exactly the kind where it's easy to find the right numbers but then answer the wrong question (writing the HCF when it asked for the LCM), so double-check you've answered what was actually asked.
Exit ticket: Two buses leave the same stop, one every 8 minutes, one every 12 minutes. They just left together. How many minutes until they leave together again?
Friday — Consolidation
Today's not about new content, it's about locking in this week's ideas.
Quiz (10–15 min): Topmarks — Multiples and Factors, or if you'd rather mix everything from the week together, Transum's Factors hub has a spread of games and quizzes covering factors, multiples and primes in one place.
Weekend printable: MEP GCSE Pupil Text 1 — Unit 1: Indices (PDF), sections 1.4–1.5.
End-of-week reflection (5 min): In your notebook, answer:
Which topic this week felt most solid?
Which topic do you want to see again before we move on?
Rate your confidence 1–5 on: factors and multiples, prime factorisation, HCF, LCM.
Keep this reflection; we'll circle back to anything you flagged as shaky in the mixed-review session at the end of Unit 1 (Week 4), so nothing gets forgotten.
Next week: Powers, roots, and the order of operations (BIDMAS), including your first look at index laws, which will matter a lot once algebra starts in Unit 2.
