Why do so much math work on factors, when you can just lower it to the lowest common figures?

Question

Why do so much math when all you have to do is lower it as much as possible.18/24 divide by the lowest number which is two and making it 9/12.  The lowest then would be three making it 3/4.  It's the same answer you had.

 

Doing all that other math takes too long.  There may be some that would require it, then do it only then.

 

This is the way I was taught in the 50's.

Answer 1

I think I would need a bit of comparison to what sort of factors we're looking at, but essentially what you just did was find the factors that are common with both numbers, two and three, or with them together, a six.

 

If you mean why find six in the first place, it may just be to recognize that bigger numbers work and take larger chunks at once.