What is 3.8 percent of 640 - step by step solution

To get the solution, we are looking for, we need to point out what we know.

1. We assume, that the number 640 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 640 is 100%, so we can write it down as 640=100%.
4. We know, that x is 3.8% of the output value, so we can write it down as x=3.8%.
5. Now we have two simple equations:
1) 640=100%
2) x=3.8%
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:
640/x=100%/3.8%
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for what is 3.8% of 640

640/x=100/3.8
(640/x)*x=(100/3.8)*x       - we multiply both sides of the equation by x
640=26.315789473684*x       - we divide both sides of the equation by (26.315789473684) to get x
640/26.315789473684=x
24.32=x
x=24.32

now we have:
3.8% of 640=24.32