HCF and LCM · म.स. और ल.स.
Biggest common factor, smallest common multiple — and which one a word problem needs.
HCF and LCM games
HCF and LCM
- HCF (Highest Common Factor, महत्तम समापवर्तक): the biggest number that divides both. HCF of 12 and 18 = 6.
- LCM (Lowest Common Multiple, लघुत्तम समापवर्त्य): the smallest number both divide into. LCM of 4 and 6 = 12.
- Prime factor method: 12 = 2 × 2 × 3, 18 = 2 × 3 × 3. HCF = common primes = 2 × 3 = 6. LCM = all primes, each the most times it appears = 2 × 2 × 3 × 3 = 36.
- For two numbers: HCF × LCM = the two numbers multiplied.
- Word problems: “biggest equal pieces / most per group” → HCF; “together again / smallest number both divide” → LCM.
For Class 5 to 7. See also prime numbers, factors and multiples.
A one-page chart to stick on the wall, and a worksheet to practise.
HCF and LCM
HCF and LCM
- HCF (Highest Common Factor, महत्तम समापवर्तक): the biggest number that divides both. HCF of 12 and 18 = 6.
- LCM (Lowest Common Multiple, लघुत्तम समापवर्त्य): the smallest number both divide into. LCM of 4 and 6 = 12.
- Prime factor method: 12 = 2 × 2 × 3, 18 = 2 × 3 × 3. HCF = common primes = 2 × 3 = 6. LCM = all primes, each the most times it appears = 2 × 2 × 3 × 3 = 36.
- For two numbers: HCF × LCM = the two numbers multiplied.
- Word problems: “biggest equal pieces / most per group” → HCF; “together again / smallest number both divide” → LCM.
kheloaurseekho.in — free charts, games and worksheets
HCF and LCM — worksheet
Name: ____________________ Class: ______ Date: __________
1. HCF of 16 and 24 = ____ HCF of 27 and 45 = ____
2. LCM of 6 and 9 = ____ LCM of 8 and 12 = ____
3. Write 60 as a product of primes: ______________
4. Two lights blink every 4 and 6 seconds. After how many seconds do they blink together? ____
5. Find the HCF and LCM of 18 and 24, and check that HCF × LCM = 18 × 24.
kheloaurseekho.in — free charts, games and worksheets
