Introduction to proportion
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Transcript of Introduction to proportion
![Page 1: Introduction to proportion](https://reader037.fdocuments.in/reader037/viewer/2022100601/557e2250d8b42a08748b551b/html5/thumbnails/1.jpg)
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.
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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.
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)
Students says, length: breadth= 2:1
Ratio of three sides is, 6:7:8
1) a) l:b = 3:1b) 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
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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)
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.
3) a) A:B = 1:5b) C:D = 2:10
4) a) A:B:C= 1:2:3b) P:Q:R=2:4:6 =1:2:3
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 = 2:3They are proportional
1:4 = 1:44:16 = 1:4They are proportional
3:5 = 3:59:10= 9:10 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
ab= pq
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Group activity 2 To confirm the concept, teacher gives activity sheets to each group.
Group activity 3
12:15 = 4:516:13 = 16:13They are not proportional
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 = 24:1616×d = 2×24 d = 3
10:4 = f:28 4×f = 10×28 f=70
8:n = 32:20
Solve the proportions given below.
4:p = 8:14 d:2 = 24:16 10:4 = f:28 8:n = 32:20
2:8 = 1:4 1:15 = 3:45 36:42 = 6:7 1:19 = 4:76
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Group activity 4 Then the teacher says that they will be given four numbers. Use the numbers to create an equivalent proportion.
Review
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:
32×n = 8×20 n = 5
Students will observe the activity sheet.
1) 3:2 =9:62) 1:7 = 14:23) 12:144 =1:124) 1:3 = 1:2
12:36 = 1:3They 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?
given Proportion1) 3,2,9,62) 1,7,2,143) 12,144,1,124) 1,6,2,3
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