You must first calculcate what is in between the parentheses. Firstly, you add 3/8 + 3/4 (as shown in the beginning) to get 1.125. Second, you add 1/3 plus 1/6 (shown in the second part of the equation) to get 0.5. Lastly, you're left with 0.625 after subtracting 0.5 from 1.125.
