GCD and LCM Explorer
Playing with Numbers · Class VI
Slide two numbers and watch their greatest common divisor and lowest common multiple.
- GCD(a, b)6
- LCM(a, b)36
- Product check216
Formulas in this lab
- GCD(a, b)
- LCM(a, b)
- Product check
Frequently asked questions
▶What is the difference between GCD and LCM?
GCD is the greatest common divisor, the largest number that divides both a and b. LCM is the lowest common multiple, the smallest number both a and b divide into. For 12 and 18, GCD is 6 and LCM is 36.
▶How do I use the GCD and LCM lab?
Slide a and b between 1 and 60. The lab uses the Euclidean algorithm to compute GCD and then finds LCM as a*b divided by GCD. Try 24 and 36 to see GCD = 12 and LCM = 72.
▶How is LCM used in real life?
LCM helps when two events repeat at different cycles. If one bell rings every 12 minutes and another every 18 minutes, both ring together after LCM(12,18) = 36 minutes. School bells, traffic lights and festival cycles all use this idea.
▶GCD vs HCF: are they the same thing?
Yes, GCD (Greatest Common Divisor) and HCF (Highest Common Factor) are two names for the same number. Indian textbooks usually say HCF while international ones say GCD. The lab labels it GCD, but you can write it as HCF in your school exam answer.