Well 6.125 is simply 6 + 0.125. 0.125 is simply 1/8 (you can figure this out if you divide 1 by 0.125, you will get a result of 8 meaning that 0.125 goes into 1 eight times, and therefore 0.125 is one-eighth). So we have: 6.125 = 6 + 1/8. Well 6 is just 6 * 8/8 (multiplying by one in the form of 8/8) and we get 48/8. So we have: 6.125 = 6 + 1/8 = 48/8 + 1/8 = 49/8.