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?
Join the small live online batch (max 20 students) — weekly tests, doubt solving and a parent report card. Or start with a free demo class.