MATHEMATICS PRIMARY 5 SECOND TERM LESSON NOTE SCHEME OF WORK
SUBJECT: MATHEMATICS
CLASS: BASIC FIVE
WEEK TOPIC
- RATIO AND PERCENTAGE
- SIMPLE PROBLEMS ON PERCENTAGE
- MONEY: profit and loss
- MONEY: SIMPLE INTEREST
- MONEY: DISCOUNT AND COMMISION
- PERIMETER OF PLANE SHAPES
- AREA OF RIGHT ANGLED TRIANGLE
- VOLUME
- PROBLEM ON WEIGHT
- AVERAGE SPEED
- WEEK ONE
RATIO AND PERCENTAGE
Meaning of ratio
The relation between two quantities (both of the same units) obtained by dividing one quantity with another is called ratio. Ratio can be denoted by using the symbol ( : ).
EXAMPLE 1
What is the ratio between the weight two bags of sugar of 4kg and 6kg respectively?
Solution
Ratio of weights of bags of sugar = 4kg/ 6kg = 2/3 = 2:3
EXAMPLE 2
A pole of length 165cm is divided into two parts such that lengths are in the ration 7:8. Find the length of each part of the pole?
Total ratio = 7 + 8 = 15
First part = 7/15 , second part = 8/15
Length of first part = 7/15 of 165cm
= 7/15 × 165
= 7 x 11 = 77cm
1 x 1
Length of second part = 165cm – 77cm = 88cm
DIRECT PROPORTION
Examples
- A marker costs $18. Calculate the cost of 5 markers.
- A student went to the market to purchase textbooks. He purchased two textbooks for $24
- What is the price of one notebook?
- What would be the price of 5 such note
Solution
- If one marker = $18
5 markers = $18 x 5 = $90
- 2 textbooks = $24
1 textbook = m
2 × m = 1 x $24
2m = $24
M = $24 ÷ 2 = $12. Therefore 1 textbook = $24
(b) Since 1 textbook = $12
5 textbooks = $12 × 5 = $60
Equal and equivalent ratios
- The two ratios below are equal or equivalent.
1/2 = 4/ 8
3/5 = 6/10
- The two ratio below are not equal or equivalent
4/3≠6/10 3/5≠7/15

EVALUATION
- What is ratio?
- Find the ratio of each of the following in its lowest terms:
- 24cm: 72cm
- 425km: 750km
- 75min: 150min
- 85kg: 102kg
- A field is 50m in length and 60m in width. Find the ratio between its width and length.
- A scooter can travel 225km with 5 litres of petrol. How many litres of petrol is needed to travel 675km?
WEEK TWO
SIMPLE PROBLEMS ON PERCENTAGES
Percentages are fractions with 100 as denominator
EXAMPLE 1
Change the following fractions to percentages
- 2/5 = 2/5 of 100 = 2/5 × 100 = 200 = 40%
5
EXAMPLE 2
Change these percentage to fractions
- 75% = 75 = 15 = 3
100 20 4

EXAMPLE 3
Change 7 ½% to fractions in their lowest terms
Solution
7 ½ % = 7 ½ out of 100
= 15/2 × 1/100
= (15 × 1) ÷ 200
= 15 ÷ 200 = 3/40

EXERCISE
Change the following fraction to percentage
- 2/5
- 2/4
- 3/30
Change to fractions in their lowest terms
- 66 ½ %
- 12 ¼ %
- 16 2/3 %


MEANING OF PROFIT
When the selling price of an article is higher or greater than the cost price, we have a profit or gain.
Profit = selling price – cost price
MEANING OF LOSS
When the selling price is less than cost price we have a loss.
Loss = cost price – selling price
