In working through a percentage formula, there are usually three
variables in play: The whole number, a part thereof and the percentage.
An easy way to organize this information is in a quadrant grid.
Percentage Calculator grid:
If you know two of the variables in your equation, it is very
easy to calculate the third.
1.) Take the two known diagonal quadrants and multiply them.
2.) Now divide your answer from the first step by the remaining
3.) That's it!
Okay, let's say Jack has 43 beans and he sells 28 of them, what
percentage did he sell?
We would set it up like this:
28 X 100 = 2800
2800 divided by 43 = 65.1
The answer is 65 percent (rounded).
Now let's give Jack 60 beans, he needs to give his mother 45 percent
of them. How many beans does he need to give his mother?
60 X 45 = 2700
2700 / 100 = 27
He would give his mama 27 beans.
And that's how easy it is to calculate percentage. Finding the whole
number works the same way.