You find a common denominator (the bottom one) and then add the numerator (the top) but you don't add the denominator, you just make it the same
It's difficult to make out, but I think the task is to expand

Write the number in polar form first:

By DeMoivre's theorem, you have

and converting back to Cartesian form, this number is equivalent to
5^3 Sartre 10 + 4^3 sqrt 10
12 6 1/4 pieces can be cut out.
Total of 2.7. ---Anna had 0.5 Sam 0.75 Michelle 0.45 and Paige 0.70