7/8 = 7 * 1/8 and 1/8 = 1 : 8 = 0.125. After that: 7 * 0.125 = 0.875. Finally, 0.875 > 0.78. We can do it also by transforming 0.78 to fraction: 0.78 = 78/100 = 39/50 and then multiplying the numerator and the denominator by 4: 39/50 = 156 / 200 . Then we will also multiply 7/8 * 25/25 = 175/ 200. Obviously: 175/200 > 156/200. Answer: 7/8 is bigger than 0.78.