Lesson 10: Averages.Mathswatch 41/133

GCSE Maths Starter 10

2. Write 56 as a product of its prime factors.

3. Simplify (y⁵)³ 4. Solve 4(x + 7) = 36

5. Describe fully the single transformation that maps A onto B.

1) Find the median and the range in the stem and leaf below.

• To calculate the mean, median, mode and range from a list of data.

• To estimate the median and modal group from grouped data.

• To estimate the mean from data in a table.EXTN: To solve problems involving mean from a table when the table isn’t drawn for you.(Grade C)

Lesson 10: Averages.Mathswatch 41/133

Lesson 10: Averages.Mathswatch 41/133

Play this youtube clip: http://www.youtube.com/watch?v=zzDDUc_yP2I

So… Most Common• If we know:

• The Mode = Most Common

• What is the mode average of the following numbers?

2, 6, 4, 2, 5, 8, 7, 4, 2, 6, 3, 2, 2, 3

Lesson 10: Averages.Mathswatch 41/133

So… Median = Middle• You need to put the numbers in order; from

the lowest to the highest

• And find the halfway point:

2, 6, 4, 2, 5, 8, 7, 4, 2, 6, 3, 2, 2, 3

Lesson 10: Averages.Mathswatch 41/133

The Mean• Think of a mean old man counting out his

money!

• He adds all of the values together and divides the total by the number of values he has.

Lesson 10: Averages.Mathswatch 41/133

So… calculation of the mean• Add together the numbers:2 + 6 + 4 + 2 + 5 + 8 + 7 + 4 + 2 + 6 + 3 + 2 + 2 + 3

= ?And divide by the total by the number of values

you have

Lesson 10: Averages.Mathswatch 41/133

56 14 = 4

The Range• Take the highest value and subtract the lowest

value:

2, 2, 2, 2, 2, 3, 3, 4, 4, 5, 6, 6, 7, 8

Answer: 8 – 2 = 6

Lesson 10: Averages.Mathswatch 41/133

Lesson 10: Averages.Mathswatch 41/133

For averages from a table Watch Mathswatch clip 133.

Mathswatch Website

Centre ID: bbsLogin: burtonPassword: radius

Lesson 10: Averages.Mathswatch 41/133

One for You MP MP x Freq

2 x 5 = 10

120225

245

18045

35

25

15

5

30 780 ÷ 30 = 26

Often it tells you what to divide by in

the first sentence

• To calculate the mean, median, mode and range from a list of data.

• To estimate the median and modal group from grouped data.

• To estimate the mean from data in a table.EXTN: To solve problems involving mean from a table when the table isn’t drawn for you.(Grade C)

Lesson 10: Averages.Mathswatch 41/133