...to a percentage? I know that 0.5 = 5/10 = 1/2 = 50%. But I'm not sure why multiplying 0.5 and 1/2 by 100 gives us them as a percentage. Take 1/2. Multiplying it by 100 means multiplying the numerator by 100. So 1/2 becomes 100/2 which gives 50 (50%). I can see that it works. But I don't know why. Likewise for decimals. I have had a stab at it. To turn 1/2 into a percentage (without using the multiply by 100 method) I would look at how to turn the denominator into a 100 (multiply by 50 in this case) and then multiply the numerator by 50 also. This is effectively multiplying the whole thing by 50/50 - but 50/50 equals 1. Likewise for multiplying 1/4 by 25/25. What am I missing here?