REFERENCE BOOK: Macmillan Progressive Mathematics for JS2 Page 23
BEHAVIOURAL OBJECTIVES: At the end of this lesson, students should be able to:
(1) Explain the meaning of profit
(2) Explain the meaning of loss
(3) Solve problems on profit and loss.
CONTENTS
Profit is the amount realized over the cost price of an item.
(1) Profit = Selling price - cost price
(2) Selling price = cost price + profit
(3) Cost price = selling price - profit
(4) Loss = cost price - selling price
EXAMPLE 1:
An article was bought for #200 and sold for #250. What is the profit?
Cost price = #200.
Selling price = # 250
Profit = SP - CP
#250 - #200
#50
EXAMPLE 2:
A radio which cost #3000 was sold at a profit of #600. Find the selling price.
Selling price = CP + PROFIT
Cost price = #3000
Profit = #600
Selling price = #3000 + #600
#3600
EXAMPLE 3
An article was sold for #1500 at a profit of #200. Find the cost price.
Cost price = SP - PROFIT
= #1500 - #200
= #1300
Loss = cost price - selling price
Example : A man bought a dozen mangoes for #180 and sold each of them for #10. Find the loss.
solution
Cost price = #180
Selling price = 12 x #10
= #120
Loss = #180 - #120
= #60
EVALUATION: Macmillan Progressive Mathematics for JS2 Page 24 Exercise 3 Questions 1, 2 and 7
ASSIGNMENT: Answer questions 8, 9 and 10 from Macmillan Progressive Mathematics 2, Page 24 Exercise 3.
further studies
http://www.mathsteacher.com.au/year9/ch ... profit.htm
http://www.mathsteacher.com.au/year9/ch ... s/loss.htm
http://www.bbc.co.uk/scotland/learning/ ... rev1.shtml
practice test
http://www.bbc.co.uk/scotland/learning/ ... ofit_loss/
LESSON 118
TOPIC: Percentage profit or loss
REFERENCE BOOK: Mathematics Inside Out Page 121
BEHAVIOURAL OBJECTIVES: At the end of this lesson, students should be able to:
(1) Find percentage profit
(2) Find percentage loss.
CONTENTS
Example:
Percentage profit = gain/cost price x 100
Percentage loss = loss/cost price x 100
Example 1:
A man bought a bag for #250 and sold it for #300. Find the gain %
Cost price = #250
Selling price = #300
Gain =#300 - #250 = #50
% gain = [sup]50[/sup]/[sub]250[/sub] x 100%
20%
Example 2:
An article was bought for #500 and sold for #450. Find the loss%
Cost price = #500
Selling price = #450
Loss = #50
Loss% = [sup]50[/sup]/[sub]500[/sub] x 100%
10%
EVALUATION: Mathematics Inside Out Page 122, exercise 14.9, questions 5, 6 and 7.
ASSIGNMENT: Answer questions 2, 3 and 4 from Mathematics Inside Out, Page122, exercise 14.9
further studies
http://www.mathsteacher.com.au/year9/ch ... htm#profit
http://www.mathsteacher.com.au/year9/ch ... s.htm#loss
practice test
http://www.bbc.co.uk/scotland/learning/ ... ofit_loss/
LESSON 119
TOPIC: Finding the cost price when given the selling price and gain or loss%
REFERENCE BOOK: Mathematics Inside Out, Page 123
BEHAVIOURAL OBJECTIVES: At the end of this lesson, students should be able to calculate the cost price given selling price and gain or loss%
CONTENTS
Example: What is the cost price of an article, given the selling price and gain% as #40 and 25% respectively?
Selling price = #40
Gain% = 25%
X = 100% + 25% = 125
CP/40 = [sup]100[/sup]/[sub]125[/sub]
125CP = 40 x 100
CP = [sup]4000[/sup]/[sub]125[/sub] = #32
EXAMPLE 2
By selling an article for #35, a trader loses 30%. How much did he buy it?
Selling price = #35
Loss% = 30%
X = 100% - 30% = 70%
CP/35 = [sup]100[/sup]/[sub]70[/sub]
70CP = 3500
CP = [sup]3500[/sup]/[sub]70[/sub]
CP = #50
EVALUATION: Answer questions 2 and 9 from Mathematics Inside Out Page 124.
ASSIGNMENT: Answer questions 3 and 8 from Mathematics Inside Out Page 124
further studies
http://www.csgnetwork.com/retailsalescalc.html
LESSON 120
TOPIC: Finding the selling price when the cost price and gain or loss% are given.
REFERENCE BOOK: Mathematics Inside Out, Page 124.
BEHAVIOURAL OBJECTIVES: At the end of this lesson, students should be able to find the selling price when cost price and gain or loss% are given.
CONTENTS
Example
Find the selling price of an article which was bought for #600 and sold at a loss of 25%.
Cost price = #600
Loss% = 25%
X = 100% - 25%
X = 75
600/SP = [sup]100[/sup]/[sub]75[/sub]
100SP = 600 X 75
SP = #450
EXAMPLE 2
A trader bought an article for #75 and sold it at a profit of 24%. Find the selling price.
Cost price = #75
Gain% = 24%
X = 100% + 24%
X = 124
75/SP = [sup]100[/sup]/[sub]124[/sub]
100SP = 75 X124
SP = 9300/100
SP = #93
EVALUATION Answer questions 6 and 7 from Mathematics Inside Out, Page 124.
ASSIGNMENT Answer questions 8 and 9 from Mathematics Inside Out, Page 124.
further studies
http://www.buildingtrade.org.uk/article ... argin.html
