Lesson Notes By Weeks and Term - Primary 4

WEEK 5

SUBJECT: MATHEMATICS

CLASS: PRIMARY 4

TERM: 3RD TERM

TOPIC: Capacity

SUBTOPIC:  Capacity addition and subtraction of liters

BEHAVIOURAL OBJECTIVES: At the end of the lesson, pupils should be able to:

1. Recapitulate the standard measurements of some liquid
2. Convert liters to centiliters
3. Add liters correctly
4. Subtract liters correctly

CONTENT

CAPACITY ADDITION AND SUBTRACTION IN LITERS

Capacity is the measure of the amount of liquid in a container. The standard unit of

measuring capacity is the litre ( l

Small amount of liquid is measured in millilitre (ml) while large amount is measured in litres.

Table of capacity measure

10 milliliters ( ml) = 1 centiliter ( cl) 10 centilitres = 1 decilitre (dl)

10 deciliters = 1 litre (l) 10 litre = 1 decilitre (dl)

10 decilitres = hectolitre (hl)  10 hectolitres = 1 kilolitre (kl)

Note that

1 000ml  = 1 litre ( l ) 100 cl = 1 litre 1 000 l = 1 kilolitre (kl)

When converting a smaller capacity measure to a higher one, note the following:

1. a) From ml to cl, divide by 10 b) From cl to l, divide by 100
2. c) From ml to l, divide by 1 000 d) From l to kl, divide by 1 000

Examples

1. Convert 4 000ml to l =4000/1000l=4l
2. Convert 600cl to l = 600/100=6l

Exercise 1

Express the following in litres L

1. 2 000ML 2. 1 200CL 3. 650cl 4. 800cl 5. 5 000ml
2. 20 000ml 7. 900ml 8. 14 000ml 9. 700ml 10. 10 500ml

When converting higher capacity measure to a smaller capacity, note the following:

1. a) From cl to ml, multiply by 10 b) From l to cl, multiply by 100
2. c) From l to ml,, multiply by 1 000 d) From kl to l, multiply by 1 000

Examples

1. Convert 6 litres to cl

1l = 100 cl

6l = 100 × 6 = 600 cl

2. Convert 5.5l to ml

1l  = 1 000 ml

5.5l = 5.5 × 1 000 ml = 5 500ml

Exercise 2

Convert the following to ml

1. 7 cl 2. 6.5l 3. 10 l 4. 8.5 l 5. 12l

Convert the following to ml

1. 2 l 2. 10 cl 3. 1.5 l 4. 3 cl 5. 4 l

Convert the following to l

1. 1.5 kl 2. 3kl 3. 4.3 kl 4. 0.8kl 5. 0.26kl

6. 1.2 kl 7. 0.3 kl 8. 0.15 kl 9. 1.04 kl 10. 3.13kl 

Addition and subtraction involving litres

Examples

1. 2.38l + 1.65l

         = 2 · 38l+ 1 · 65 =4 · 03 l

2. 46.35l – 29.l6 l

            = 46 · 35 – 29 · 16 = 17 · 19l

Exercise

Copy and complete the following.

1. 4 · 3 + 2 · 4l

2.7 · 9+ 8 · 6l

3. 14 · 3+ 9 · 8l
4. 8 · 42+ 3 · 25l
5. 5. 12 · 86+ 4 · 91
6. 15 · 63+ 14 · 78
7. 3 · 175+ 18 · 134
8. 13 · 217+ 19 · 893
9. 27 · 398+ 24 · 923
10. 34 · 654+ 27 · 678
11. 49 · 415+ 50 · 687
12. 5 · 6− 2 · 4l
13. 9 · 2− 5 · 4l
14. 11 · 8− 6 · 9
15. 7 · 43− 2 · 19l
16. 20 · 24− 8 · 77l
17. 32 · 03− 18 · 15l
18. 32 · 714− 16 · 250l
19. 46 · 038− 15 · 71l
20. 53 · 412− 26 · 891l
21. 60 · 105− 42 · 314l
22. 76 · 964+ 9 · 087
23. 795 · 22+ 900 · 11l
24. 900 · 85+ 25 · 22
25. 18.23l + 19.47l 26. 26.08l + 34.971l 27. 41.376l + 39.8l
26. 30.317l – 12.888l 29. 46.053l – 18.94l 30. 61.7l – 45.632l