What is % of ?

2.73

The purpose of solving this problem is to determine what 21% of 13 is. One common real life problem where a solution like this may be helpful include calculating how much tip to leave at a restaurant. Solving this problem requires two simple math operations that you can perform on any calculator. The first step is a division and the second step is a multiplication. Here's a cool tip though, you can actually reverse the order of these operations and the result will be the same! Here are the steps:

Step 1: Divide 13 by 100

In this case, the number that we are "comparing" to 100 is 13, so we must first normalize the number by dividing it by 100. The operation we have to solve is this: $$ \frac{13}{ 100 } = 13 \div {{ 100 }} = 0.13$$

Step 2: Multiply 0.13 by 21 to get the solution

Now that we have our normalized number, 0.13, we just have to multiply it by 21 to get our final answer. The forumla for this is obviously quite simple: $$ 0.13 \times 21 = 2.73 $$

That's all there is to it! Note that you can replace these values with new ones from any similar problem.