The document presents a mathematics lesson focused on calculating the average, defining it as a single figure representing a group of data. It provides various examples, including savings, scores, and heights, along with step-by-step instructions on how to compute averages and practical applications. Additionally, it includes practice questions and assignments for students to complete.

1. Ch 10 : Average
Lesson 1 : Average
OSP ROUND (II) Week 5
Mathematics

2. OBJECTIVE
• You will be able to find
the average, given the total
value and the number of data
the total value, given the average
and the number of data

3. Days Amount Saved
1 50
2 60
3 40
4 80
5 50
6 40
7 30
Total 350

4. You can save this money easily with the
help of average.
An average is a single figure that
represents the whole group
Steps to find average:
1. First we add all the money.
2. Then divide the total money by how many days
are there.
Average = Total of amount saved
Total no. of days
Average = 350
7 Average = Rs. 50

5. Five children played a computer game and their
score in the first level are shown in the bar graph
58
32
46 48
36
0
10
20
30
40
50
60
70
Ali Ahmed Farhan Bina Ayesha
Grade Score
What is the
average score
of 5 children?

6. Average score = 44
5
220
Total
Average Score =

7. Let’s Solve
Q5: 3 children have an average of
43 stickers each. How many
stickers do the 3 children have
altogether?

9. LET’S PRACTICE
Q 11 : The average height of 3 boys was 156 cm.
When a girl joined them , the average height of the
4 children was 153 cm. How tall was the girl?

10. The average height of three boys was
156 cm.

11. The average height of three boys was 156 cm.
When a girl joined them the average height of
four children was 153 cm. How tall was the girl?

12. Total height of three boys = 156 X 3
= 468 cm
Total height of three boys and 1 girl
= 153 X 4
= 612 cm
Height of the girl = 612 – 468
= 144 cm
So the girl is 144 cm tall.

13. ,
 The average is the mean value of numbers. It is easy to calculate.
 Add up all numbers. Then divide the sum by how many numbers
there are. The most practical application of average is the marks of
individual subjects. Suppose marks obtained in four different math’s
tests are
13
15
,
15
15
,
14
15
and
11
15
so the average marks obtained is
calculated as : total marks obtained=13+ 15+14+ 11 = 53,
number of tests= 4,
average marks = = 13.25 13 marks out of 15
General formula for average is = average

14. 1. Practice Q 1-6 Textbook page 222
2. Work sheet 1 Q(1-6) Work book page 90-92
ASSIGNMENT
Written Work On Note Book
Submit till Saturday 8.p.m

15. THANK YOU