Subject : Mathematics

Class : Basic 6 / Primary  6  /Grade 6

Term : Third Term / 3rd Term

Week : Week 7

Topic : Elementary Everyday Statistics Mean, Median and Mode

Behavioural Objectives :  At the end of the lesson, the pupils should be able to

• Explain the meaning of mean , median and mode 
• Solve simple sums on mean , median and mode

Previous Knowledge : Pupils have previous knowledge of      Types of Angles and Shapes     that was taught in the previous lesson

Instructional Materials :

• Pictures
• Wall Posters
• Related Online Videos
• Role Playing

Reference Materials

• Scheme of Work
• Online Information
• Textbooks
• Workbooks
• 9 Year Basic Education Curriculum

Content :

Elementary Everyday Statistics Mean, Median and Mode

Mean : This is obtained when sums of specific set of numbers is divided by the number of those specific numbers

Median : This is obtained when a given set of number is arranged either in ascending order ( from the smallest to the biggest ) or in descending order (from the biggest to the smallest ) and the middle number is chosen

Mode : Mode is the number that has the highest  frequency . It is the number that appears most

EVERYDAY STATISTICS

Exercise 2
Write these figures in tally marks.
1. 13 2. 22 3. 19 4. 25 5. 31 6. 4
7. 29 8. 24 9. 36 10. 43

Mode
Mode is the item or number that occurs most frequently in a given data. To find the mode of
a given data, arrange the numbers in order of magnitude, then count the number of times
each number occurs.

Example
The following are the scores of fifteen pupils in a mathematics test: 100%, 84%, 92%, 84%,
67%, 88%, 84%, 45%, 35%, 84%, 24%, 20%, 54%, 64% and 10%. Study the solution to find
the mode of the score.

Solution
Arrange the scores in order of magnitude to enable you to note the mode clearly.
100%, 92%, 88%, 84%, 84%, 84%, 84%, 67%, 64%, 54%, 45%, 35%, 24%, 20%, 10%
The mode of the scores = 84%.

We can also prepare a table as follows.

Scores % Number of times Scores % Number of times
100 1 45 1
92 1 35 1
84 6 24 1
67 1 20 1
58 1 0 1
Unit 1
255

Exercise 1
Find the mode of each set of data.
1. 1, 6, 7, 5, 8, 9, 6, 3,

2 2. 3, 7, 8, 4, 0, 0, 0, 6, 5, 9, 10

3. 5, 2, 5, 6, 8, 6, 2, 2

4. 4, 5, 6, 7, 7, 0, 2, 1, 7, 6, 8

5. 4, 7, 6, 7, 5, 9, 5, 7, 8 5

6. 2, 5, 7, 6, 8, 3, 8, 9, 7, 8

7. 9, 3, 4, 5, 9, 6, 7, 8, 0, 2

8. 10, 2, 4, 6, 8, 7, 9, 10, 10, 0

9. 7, 5, 6, 4, 5, 6, 3, 8, 7

10. 4, 6, 9, 7, 9,

MEAN
Mean is the average of a given set of numbers. To find the mean, add up all the numbers,
then divide by how many numbers that are in the set.
Mean = Sum of the numbers/Numbers in the set

Example
The mean of the following set of numbers has been calculated:
36, 59, 54, 20, 82, 61, 48, 42, 58 and 40
Solution
Mean = 36 + 59 + 54 + 20 + 82 + 61 + 48 + 42 + 58 + 40/10
= 500/10
= 50
256

Exercise
Find the mean of each set of the following scores.
1. 50%, 85%, 70%, 45%, 90%, 68%, 98%, 25%, 63%, 39%
2. 14%, 91%, 40%, 73%, 88%, 60%, 55%, 59%
3. 32%, 24%, 53%, 68%, 92%, 81%, 47%, 76%, 40%, 87%, 61%, 23%

Answer these questions.
4. The pulse rates of six patients are as follows: 59, 36, 48, 51, 62, 68. Find the mean of
the pulse rate.
5. The following are the scores of fifteen pupils in a mathematics test out of 10
5, 8, 6, 9, 7, 4, 10, 2, 5, 8, 9, 0, 1, 6, 9.

Find the mean score.
6. The ages of eight pupils are shown below. Find their mean age:
13 years, 14 years, 12 years, 10 years, 11 years, 9 years, 15 years, 8 years

7. The allowances of ten students are as follows: 􀎏800.00, 􀎏1000.00, 􀎏2000.00, 􀎏1500.00,
􀎏700.00, 􀎏1800.00, 􀎏2200.00, 􀎏1700.00, 􀎏2500.00, 􀎏600.00. What is the mean
allowance?

8. The distance covered by eight cars are 120 km, 200 km, 350 km, 150 km, 250 km, 90 km,
500 km, 420 km. Find the mean of the distance covered.

Median
The median of a set of numbers is that number that is exactly at the middle of the set of
numbers when they are arranged in order of size.
To find the median, arrange the numbers in order of size, from the largest to the smallest.
The median is then the middle number.

Examples
Here the median of each of the following sets of numbers has been found.
1. 20, 30, 10, 90, 80, 100, 70

Solution
Arrange the numbers in order of size.
100 90 80 |70| 30 20 10
The median = 70

We have three numbers to the left and three to the right and 70 is at the middle.
2. 18, 20, 14, 15, 12, 16, 24, 28, 30, 25
Solution
Arrange the numbers in order of size
30 28 25 24 |20 18| 16 15 14 12

Since there is no middle number the median is the mean of the two middle numbers.
Median = 20 + 18/2
= 38/2
= 19

Exercise
Find the median of each of the following sets of numbers:
1. 9, 12, 14, 20, 15, 32, 41, 35, 40
2. 218, 314, 420, 117, 510, 250, 340, 480, 550, 180, 390
3. 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180
4. 8.2, 3.5, 9.7, 10.1, 13.4, 5.5, 17.6, 12.3, 11.4
5. 40, 20, 80, 60, 100, 140, 120, 180, 160, 200, 240, 220
6. 170, 230, 190, 150, 130, 250, 240, 300, 330
7. 111, 222, 333, 414, 515, 616, 720, 820, 920, 1120
8. 8 cm, 10 cm, 14 cm, 18 cm, 22 cm, 24 cm, 12 cm, 26 cm, 11 cm, 17 cm, 25 cm
9. 27 kg, 30 kg, 14 kg, 32 kg, 45 kg, 54 kg, 23 kg
10. 40 litres, 30 litres, 53 litres, 26 litres, 64 litres, 70 litres, 82 litres, 90 litres, 100 litres

Frequency tables can be drawn from your experiments of:
􀁏rolling dice
􀁏tossing coins several times.
Examples
1. Bisola tossed a coin 20 times and recorded his results as follows. Study the solutions.
H T T H H
T T H T H
T H T T H
H T H T T
a) Draw a frequency table to show the experiment.
b) How many times did heads appear?
c) How many times did tails appear?
d) Express b) and c) as fraction of total outcomes.

Solution
a) Face Tally Frequency
H //// ///// 9
T //// //// / 11
Total 20
b) Heads appears 9 times.
c) Tails appears 11 times.
d) i) The fraction of heads appearing is 9/20
ii) The fraction of tails appearing is 11/20

Presentation

The topic is presented step by step

Step 1:

The class teacher revises the previous topics

Step 2.

He introduces the new topic

Step 3:

The class teacher allows the pupils to give their own examples and he corrects them when the needs arise

Evaluation :

Assignment :

Prepare for the next lesson by reading about

Types of Angles and Shapes