To get the solution, we are looking for, we need to point out what we know. 1. We assume, that the number 64 is 100% - because it's the output value of the task. 2. We assume, that x is the value we are looking for. 3. If 100% equals 64, so we can write it down as 100%=64. 4. We know, that x% equals 16 of the output value, so we can write it down as x%=16. 5. Now we have two simple equations: 1) 100%=64 2) x%=16 where left sides of both of them have the same units, and both right sides have the same units, so we can do something like that: 100%/x%=64/16 6. Now we just have to solve the simple equation, and we will get the solution we are looking for. 7. Solution for 16 is what percent of 64 100%/x%=64/16 (100/x)*x=(64/16)*x - we multiply both sides of the equation by x 100=4*x - we divide both sides of the equation by (4) to get x 100/4=x 25=x x=25 now we have: 16 is 25% of 64

16 / 64 is the same as 1/4 because 16 is 1/4 of 64. 1/4 in percent form is 25% So, 16 is 25% of 64.