How to Calculate Averages

Calculating averages is a skill used throughout life for many reasons. You may need to average speed among a group of runners. You may want to find the average height of a group of people. You may want to find the average (median) age in a group. You may want to find your average grade in a class based on test results. You may want to find the average speed it takes to drive from one point to another. Calculating averages is actually very easy. In fact, it can be fun to do. Here are directions for calculating averages.

Things You'll Need

• Pencil
• Paper
• Data

Instructions

1. 

   Collect the data. In math, the data will be a group of numbers. In a math problem this information may already be given to you or you may have to read a math problem to find it. In real life, you may have to collect this information for yourself by doing a bit of research. In this example, let's find the average grade for a semester based on test scores.

2. 

   Add the data, which in this case are your test scores. In this case, let’s say that you scored, 100, 100, 97, 87, 65, and 79 on your tests. You did very well on some tests, but on others, you did not do well. To find your grade, you would find the average of the good, the bad, and those that fall in the middle as well. The scores added together equal 528.

3. 

   Count the number of data that you have. In this case, you have six pieces of data as you have taken six exams over the course of the semester. Always double check to make sure the numbers you are adding together equal the number of pieces of data. It is easy to accidentally add a number twice or to leave a number out.

4. Next, you need to divide your total test score by your data number. 528 is divided by six to find the average test score for the semester. 528 ÷ 6= ?

5. 

   Calculate the average, which in this case is 88. You can use a calculator or do the calculations by hand.

6. For fun, lets take this a step further and try to figure out your grade for the year. If you wanted to calculate your grades for the entire year, you would take the average grade from each semester and add them together. So if you got an 88 the first semester, you may have received a 90 in the second semester, a 95 in the third semester, and a 93 in the final semester. Chances are, your teacher would also have your final exam score of 90 weigh equally with your semester scores. So, you would add the numbers 88, 90, 95, 93, and 90. The sum of these numbers is 456. Divide 456 by five and your grade for the year would be 91.2. Your grade for the year would be 91%.

Tips & Warnings

• Always double check your addition and division when calculating averages.

• Always make sure to recount the number of data you are adding to be sure you don't skip a number or add one twice.

• It is also fun to average numbers in your head by first rounding the number up or down to the nearest 10.