If I have 3 m and used 3/4 m how many is left

Answer 1

I have 3m (the variable 'm' can represent anything).

...then I used 3/4 m,

3m - 3/4m = 3 - 3/4 OR 3/1 minus 3/4...

12/4 - 3/4 = 9/4

9/4 = 2 1/4 or 2.25

2.25m are left