AVERAGES

• Mathematics
• Upper Secondary (Key Stage 4)
• GCSE

24 = H in the D

28 = D in F

7 = W of the W

5 = V of the A

90 = D in a RA

What we will learn today:

• What an average is 
• Everyday uses for averages
• How to work out a mean of a set of data
• How to work out a median of a set of data
• How to work out the mode of a set of data
• How to calculate a range and what it shows

What is an average?

An average is a representative or ‘typical’ value in a set of data.

From day 1 you are being measured against an average...

Length

Circumference of head

How old are you when you sit up/crawl/walk/talk

Weight

The average person will take .............. steps a day

The average person falls asleep in .......... mins

The average person laughs ........... times a day

When do we use averages day to day?

3 Averages:

Mean

Median

Mode

Mean

Add up all the numbers and divide by how many numbers there are

Best used when:

There are no extreme values

The shoe sizes of 10 children in a school are:
5 4 6 5 7 5 2 8 6 12
What is the mean size?

The weekly costs of 5 nurseries are:
£150, £180, £130, £190, £160
What is the mean cost?

Median

Put your numbers in order

Pick the middle number

If there are 2 numbers in the middle, add them and divide by 2

Best for:

When there are extreme values in your data

Attendance in a class in your school was the following over one week: 23, 28, 21, 19, 27
What was the median attendance?

Here are the total minutes 4 toddlers slept in daycare during the day:
45, 30, 80, 60. What is the median?

Mode

The mode is the number/item which occurs the most

A class was asked how many messages they think they send on their phone each day:
50, 65, 30, 80, 50, 20, 65, 50, 40 What is the mode?

The range is a measurement of how spread out data is.

Range  = Highest number - lowest number

Maths exam results for a class were:
66%, 85%, 75%, 90%, 40%, 70%
What was the range?

Remember this:

Hey diddle diddle,

The median's the middle,

You add then divide for the mean.

The mode is the one you see the most,

and the range is the difference between.

I feel confident using averages and range

😒🙁😐🙂😃