Class 7 Maths · Ganita Prakash Part 2 · Chapter 3
Finding Common Ground
Factors, multiples, HCF and LCM — the chapter behind every “when will they meet again?” and “largest tile” problem.
Video coming soon — meanwhile, watch free classes on our YouTube channel →
Rashmi Ma’am teaches the full chapter free on YouTube — watch first, then practise below.
What your child learns
- Find factors and multiples fluently, and see how prime factorisation organises them
- Compute HCF and LCM by prime factorisation and by the division method
- Know which real problems want HCF (largest piece/group) vs LCM (next time together)
- Use the relationship HCF × LCM = product of the two numbers
- Solve the classic word problems: tiles, packing, bells ringing together, schedules
Parent pointer
The trap in this chapter isn’t the computing — it’s choosing HCF vs LCM in a word problem. A reliable rule of thumb for your child: cutting or grouping into the biggest equal pieces → HCF; waiting for things to line up again → LCM. Ask them “which one and why?” before they touch the numbers.
Stuck on this chapter? Message us — tell us the exercise number and we’ll point you to the right video.
💬 Ask about this chapterPractise it — the Azone loop
Watch the class
Full chapter above, free. Pause and solve along — that’s the rule.
Quick questions parents ask
We learned HCF/LCM in Class 6 — why again?
Class 6 introduces the ideas; Class 7 makes them powerful — prime factorisation as the master method, the HCF×LCM relationship, and harder word problems. Competitive exams ask exactly this level.
Which method should my child use — factor trees or division?
Both are taught and both are fine in exams. Division method is faster for big numbers; factor trees show the structure better. The video does each problem both ways so your child can pick their favourite.
Want this chapter to actually stick?
Take the Tallentex-style test series for Class 7 — 10 full-length timed papers, 800 questions, and a worked solution for every one. Start with the free sample test.