Introduction to proportion

1. Self Designed Innovative Lesson
Name of the
teacher
: Farsana. S Standard : VIII
Name of the
school
: St Joseph’s H.S.S Division : D
Subject : Mathematics Strength : 52/53
Unit : Ratio and proportion Date : 30/07/2014
subunit : Introduction to proportion Duration : 40 minute
Curricular statement
To learn the concept of proportion
Content analysis
Terms : part, fraction, ratio, equal, multiple, proportion.
Facts : Ratios are the simplest form of two numbers.
When two ratios are equal, then they are proportional.
Concept : The concept of proportion.
Process : The process of learning teaching and learning proportion.
Process skills : analysis, interpretation, identifying, calculation.
Definition : when two ratios are equal, where the individual quantities change,
such quantities are proportional to each other.
Learning outcomes
The pupil:
i. remembers the facts and concepts related to proportion.
ii. develops understanding the facts and concepts related to proportion.
iii. applies the above facts and concepts in new and relevant situations.
iv. discriminates the above facts and concepts related to proportion.
v. detects the facts and concepts related to proportion.
vi. designs a new idea related to proportion.
vii. develops skill in identifying proportional values.
viii. create interest in solving problems on proportion.
Pre-requisites: concept of fraction, concept of ratio.
Learning aid : chart, activity sheets, roll-up board, classroom equipments.

2. Learning strategies: group discussion, group activity.
Interaction procedure Pupil response
Introduction
To check the previous knowledge of the students,
teacher gives questions on ratio.
I. 4cm length: breadth=
8cm
II.
What is the ratio of sides of
triangle?
8cm 7cm
6cm
Then the teacher says that they are going to discuss
some examples.
3cm
1)
1cm
(a)
6cm
2cm
(b)
2)
9m 8m
7m
(a)
18m
16cm
14m
(b)
3)
A:B= 1:5
(a)
C:D= 2:10
(b)
4) A:B:C = 1:2:3
(a)
P:Q:R=2:4:6
(b)
Students says,
length: breadth= 2:1
Ratio of three sides is,
6:7:8
1) a) l:b = 3:1
b) l:b=6:2=3:1
2) a) ratio of sides is,
7:8:9
b) ratio of sides is,
14:16:18=7:8:9
3) a) A:B = 1:5
b) C:D = 2:10
4) a) A:B:C= 1:2:3
b) P:Q:R=2:4:6
=1:2:3

3. What can we say from this?
Teacher says that, very well. Even though the
measurements are different, they are having same
ratio. There is a name in mathematics for such cases
where the individual quantities change but the ratio
remains the same;”proportion”.
Group activity 1
Teacher divides the students in to groups and gives
them activity sheets.
Then the teacher displays a chart.
In all examples, the ratios are
same but the given values are
different.
Students form the group and
discuss the answers.
 2:3 = 2:3
4:6 = 2:3
They are proportional
 1:4 = 1:4
4:16 = 1:4
They are proportional
 3:5 = 3:5
9:10= 9:10
They are not
proportional
 12:15 = 4:5
16:13 = 16:13
They are not
proportional
State whether the following
ratios are proportional.
 2:3 and 4:6
 1:4 and 4:16
 3:5 and 9:10
 12:15 and 16:13
If two quantities a: b is equal to
another ratios p: q, then
푎
푏
=
푝
푞
i.e. 푎푞 = 푝푏

4. Group activity 2
To confirm the concept, teacher gives activity
sheets to each group.
Group activity 3
Group activity 4
Then the teacher says that they will be given four
numbers. Use the numbers to create an equivalent
proportion.
 2:8 = 1:4
2 ×4 = 8×1
8 = 8
 1:15 = 3:45
1×45 = 15×3
45 = 45
 36:42 = 6:7
36×7 = 42×6
252 = 252
 1:19 = 4:76
1×76 = 19×4
76 = 76
 4:p = 8:14
8×p = 4 ×14
P = 7
 d:2 = 24:16
16×d = 2×24
d = 3
 10:4 = f:28
4×f = 10×28
f=70
 8:n = 32:20
32×n = 8×20
n = 5
Students will observe the
activity sheet.
 2:8 = 1:4
 1:15 = 3:45
 36:42 = 6:7
 1:19 = 4:76
Solve the proportions given
below.
 4:p = 8:14
 d:2 = 24:16
 10:4 = f:28
 8:n = 32:20

5. Review
given Proportion
1) 3,2,9,6
2) 1,7,2,14
3) 12,144,1,12
4) 1,6,2,3
 Can we say that 1:3 is proportional to 12:36?
 Can we say that 1:7 is proportional to 70:200?
Follow up activity
Home assignment
Find the missing number
 2: = 12:30
 1:18 = :54
 3:4 =33:
1) 3:2 =9:6
2) 1:7 = 14:2
3) 12:144 =1:12
4) 1:3 = 1:2
 12:36 = 1:3
They are in proportion.
 70:200 = 7: 20
≠ 1:7
Enrichment activity
Ram worked for for 8hours and gets 400rs and Benny
worked for 6 hours and gets 300rs. Does the salary
proportional to working hours?