Arithmetic Grade Four

Lesson One hundred thirty-nine: Computing Averages

To calculate the average of a group of numbers you first find the total sum of the group of numbers and then you divide that sum by the number of numbers. 

    FIND THE AVERAGE OF: 6, 4, 5, 6, 5, 4.

    STEP ONE: 6 + 4 + 5 + 6 + 5 + 4 = 30.

    STEP TWO: 30 / 6 = 5.
Here's another example: 

     Compute the average: 21, 24, 22, 23, 22, 20.

     STEP ONE: 21 + 24 + 22 + 23 + 22 + 20 = 132

     STEP TWO: 132 / 6 = 22
You get to try a few for yourself on the next page.

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