Question

how do you add and subtract fractions with pie in the denominator?

Answer 1

well, if they have pie, I'd say, you eat it :)
once the pie has been eaten up, you'd left with the numerator only =)

Answer 2

The same way you do when the denominators are not the same. For example if you are adding the fractions 2/3 and 5/8 you would multiply both the 2 in the numerator and the 3 in the denominator by 8 and multiply both the 5 and 8 by 3 in order to get equal denominators while keeping your numerators correct. So you would get 16/24 + 15/24

Answer 3

its called taking LCM of the denominators and then simplify it...