Reach for the Star

Factors multiples and primes · Optional extension

L005 · Allow 10–15 minutes for learners ready to move on. Answers are available after an attempt.

Stretch

Find the HCF and LCM of 84 and 126 using prime factors.

Reveal a worked check after attempting

84=2²×3×7; 126=2×3²×7; HCF=42, LCM=252.

Deep challenge

Two numbers have HCF 6, LCM 180 and one number 30. Find the other.

Reveal a worked check after attempting

Product of numbers=HCF×LCM=1080; other=1080/30=36.

Recall & Review: feedback and extension integration

Lesson L005: Factors multiples and primes

Objective: Find and justify factors, prime factorisations, HCFs and LCMs; choose the right structure for a problem.

60-minute structure: 0-7 Connect & Check; 7-14 Share; 14-25 Present/model; 25-44 Apply route choice/practice; 44-52 independent exam-style check; 52-60 Recall & Review, WWW/EBI and next step.

What Went Well (WWW)

I selected an efficient numerical method, showed the key steps clearly and checked the sign, size or accuracy of my answer.

Even Better If (EBI)

I will make the place-value, sign or operation decision explicit and use estimation or an inverse calculation to check a fresh question.

Stretch and deep challenge

Stretch: Find the HCF and LCM of 84 and 126 using prime factors.

Deep challenge: Two numbers have HCF 6, LCM 180 and one number 30. Find the other.