1. Finding
The
Mean

2. Mean is another name for finding the average of a series of numbers.
Mean in Math = Average in Science

3. Mean is evening out numbers to equal amounts.5 7 8 4
How many would be in each stack if they were all made even?

4. Mean is evening out numbers to equal amounts.5 7 8 4
How many would be in each stack if they were all made even?

5. 6 Mean is evening out numbers to equal amounts. 5 7 8 4
How many are in each stack now?
The MEAN of 5, 7, 8, and 4 is 6

6. Let's Practice! 6 Find the mean of 4, 7, and 7. The mean is 4 x x x x
7 x x x x x x x 6

7. Let's Practice! 7 Find the mean of 5, 6, 9, and 8. 5 x x x x x
6 x x x x x x
9 x x x x x x x x x
8 x x x x x x x x
The mean is 7

8. Let's Practice!
The three boys weigh 108 pounds, pounds, and 112 pounds. What is the average weight of the boys?
Can you move weight from one boy to another? Let’s learn another way to find the mean when we can’t move items.

9. To find the mean you even out numbers to make them all equal.
You can find the mean by making stacks and moving items, but there is a way to do this mathematically so you can find the mean of larger numbers easier.

10. To find the MEAN, you find the sum of the numbers
To find the MEAN, you find the sum of the numbers. Then you divide the sum by the number of addends. The quotient is the MEAN!
Let’s review some vocabulary to make sure everyone understands what to do.

11. sum -
the answer to an addition problem
addends -
the numbers added in an addition problem
the answer to a division problem
quotient -
To find the MEAN, you find the sum of the numbers. Then you divide the sum by the number of addends. The quotient is the MEAN!

12. What is the sum of these numbers?
STEP ONE: To find the MEAN, you find the sum of the numbers. + + + =
300
sum -
the answer to an addition problem
What is the sum of these numbers?

13. addends – the numbers added together
STEP TWO: To find the MEAN, you find the sum of the numbers. Then you divide the sum by the number of addends.
65, 85, 70, 80
The sum is 300.
addends – the numbers added together
How many numbers did we add to get 300?
The number of addends is 4.

14. Divide the sum by the # of addends.
STEP THREE: To find the MEAN, you find the sum of the numbers. Then you divide the sum by the number of addends.
65, 85, 70, 80
sum = 300
number of addends = 4
Divide the sum by the # of addends.
300 ÷ 4 = 75

15. The quotient is the mean!
To find the MEAN, you find the sum of the numbers. Then you divide the sum by the number of addends. The quotient is the MEAN!
65, 85, 70, 80
quotient – the answer to a division problem
The quotient is the mean!
300 ÷ 4 = 75
MEAN = 75

16. To find the MEAN, you find the sum of the numbers
To find the MEAN, you find the sum of the numbers. Then you divide the sum by the number of addends. The quotient is the MEAN!
Let's Practice!

17. Let's Practice!
The three boys weigh 108 pounds, 98 pounds, and 112 pounds. What is the average weight of the boys?
108 lbs.
98 lbs.
112 lbs.
mean = 106 pounds

18. Let's Practice!
Find the average of 78, 84, and 87.
mean = 83

19. Let's Practice!
Find the average of 3, 3, 3, 5, and 6.
mean = 4

20. Let's Practice!
Find the average of 9, 7, 12, and 12.
mean = 10

21. Let's Practice!
Find the average of 300 and 310.
mean = 305