Question 1

What is the GCD of a number and 0?

Accepted Answer

GCD(a, 0) = |a|, because every number divides 0. The LCM involving 0 is usually defined as 0.

Question 2

How do I find the GCD of two large numbers by hand?

Accepted Answer

Use repeated division: divide the larger by the smaller, replace the larger with the remainder, and stop when the remainder is 0.

Question 3

Are GCF, HCF and GCD the same thing?

Accepted Answer

Yes. They are regional names for the same quantity.

Your numbers