What is the difference in the size between 1/4 and 1 1/2

1 1/2 can be rewritten as 3/2
Difference means subtraction

So we do:
3/2-1/4
To get the same denominator, we can multiply the first fraction by 2
6/4-1/4

Then we subtract the numerators and leave the denominator
So the final answer is 5/4 of 1 1/4

Hope this helps