how do we find lowest term fraction

lowest terms means you cant simplify it anymore

so if you have 4/10 that can be simplified. All you have to do is look for a factor that fits each one

4
--
10

A "2" divides equally into them

4 divided by 2 = 2
10 divided by 2 = 5

but nothing goes into 2 except 1 and 2, but neither 1 nor 2 go into 5 evenly, so youre fully simplified

some rules
things ending in 0 are always divisible by 10 (and 5)
things ending in 0 and 5 are always divisible by 5
things ending in even numbers are always divisible by 2
I believe if all the digits added up to a multiple of 3 that the number is divisible by 3 but im not sure

hope this helps :)