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Finding the Whole With the 10% Method
A couple weeks or so ago, as my class was finishing up, I ran across something that lets you use the 10% method to find the whole.
Normally, we use the 10% method to find the part or the percent. Here’s a quick review.
We set up the percentage equation by putting the part over the whole and the percent over 100. When using the 10% method, we take 10% of the whole and use that as a building block to build what we need.
Finding the part
For example, if we need 35% of 750, we start by finding 10% = 75. We double that to get 20% = 150. We then add those together to get 30% = 225.
We still need 5%, so we cut the 10% in half: 5% = 37.5. Adding that to the 30% gives us that 35% of 750 = 262.5
Finding the percentage
We can also do that backwards to find the percent. For example, if we want to know what percentage 14 is of 35, we set up our equation and find 10% = 3.5.
