How do you find the gcf of a decimal?

Answer 1

You cannot. The concept of factors makes sense only in the context of integers. As soon as you introduce fractions the concept stops making sense. Why? Because in fractional terms, every non-zero number divides into every other number.

So is 2.73 a factor of 80.9? Yes, of course. 2.73 goes into 80.9 exactly 80.9/2.73 = 8090/273 times!

Then, given any two decimals, each and every non-zero number is a common factor of both of them. The greatest common factor is then infinitely large.

Answer 2

You don't. The GCF is for integers, not decimals.