So, 5/2 could also be written as 2.5.
2.5^2 or 2.5 x 2.5 = 6.25
3/4^3 is 3/4 x 3/4 x 3/4
3/4 x 3/4 x 3/4 = 0.46875
6.25 + 0.46875 = 6.71875!