For the parents struggling to teach fractions, research suggests using pies isn’t necessarily the best way:
When two pizzas sit side-by-side, slices of one divided into sixths may not look that different from slices of another divided into fifths……..Fraction bars and number lines are considered easier than circles for children to draw and divide into parts. They also let students line up fractions in a row and see the difference in size, something they can’t do when dividing up a pie in the traditional approach.