1/8 + 1/4, you must change the denominator so that they are the same.
So that would mean 1/8+ 1/8, but since the denominator for the second one was 1/4 we must multiply the top by 2. So it becomes 1/8+2/8. You then change the denominator for the rest of them like this and it becomes 1/8+2/8+3/8+4/8+6/8+7/8 which simplified equals 7/2.
