MeanMedianMode

The average of a set of numbers, found by dividing the sum of the set by the number

of addends.

Mean

Think about when your grades are averaged in school.

MeanHere is an example: 74, 91, 63, 92, 85

74 405 ÷ 5 = 81 91 63 92

+85 405

The mean of 74, 91, 63, 92,

85 is 81.

A calculator is very helpful.

Now let’s try one together. Get your calculators ready.

Add these numbers: 100 + 85 +++ 90 75 85 =

435 is your total.

Now it is time to divide.

435 ÷ by how many numbers there are 5 =

Did you get 87?

MedianThe middle number in a set of data

that are arranged in order.Think of monkey in the middle.

Who me?

Here is an example: 1, 3, 4, 6, 7 median

            The median of 1, 3, 4, 6, and 7 is 4.

Median

Which number is in the middle?21, 16, 38, 32, 25

Here is one for you to try. You have to put them in order first!

25

The number or item that occurs most often in a set of data.

ModeWhen you think of mode, think

MOST.

Which fruit is there the most of?

ModeHere is an example: 1, 3, 4, 4, 6 4 occurs most often.

The mode of 1, 3, 4, 4, and 6 is 4. Time for you to try one. Remember, put them in order first!

31, 21, 31, 21, 21, 21 21 is the mode since it occurs most often.

Let’s listen to a song about all three!

Let’s find the mean, median and mode

of these numbers.14 ,21 ,42 ,21 ,35 ,21 ,49

Mean – Remember this is the average.First, add the numbers. 14 + 21 + 42 + 21 + 35 + 21 + 49 = 203Next, count how many numbers you have.

7Then, we divide our total 203 ÷ 7.

Our mean is 29 !

Median – Don’t forget this is the number in the middle.

17,19,21,21,21,33,42

A great strategy to help you is to mark out the numbers on the

end to get to the number in the middle.

X X

21 is the median!

Mode – Remember this is the number or item that occurs the most.

17, 21, 42, 21, 19, 21, 33

What number was repeated the most?

21 is the mode!

RangeIs the difference between the largest value and the smallest value.

Let’s go back through the slides to find the range of each set of data.

http://www.quia.com/rr/51667.html

http://www.bbc.co.uk/schools/ks2bitesize/maths/activities/modemedianmean.shtml

http://www.bbc.co.uk/schools/ks2bitesize/maths/tests/modemedianmean.shtml

Let’s at some websites.