WEIGHT.
WEEK 2&4
Topic: Weight
Objectives: At the end of the lesson, pupils should be able to:
Mention the weight of objects in grams and kilograms
Make meaningful comparisons of the weight of objects like rocks, and minerals.
CONTENT
COMPARING WEIGHT
A bottle of water weighs more than an empty bottle
A sister weighs less than a mug
A mathematics textbook weighs more than an exercise book.
Activity
A. Weigh the objects and record their weights in kilograms or grams.
1. 6 packets of whiteboard markers 2. 3 tins of Milo
3. 1 mathematics textbook 4. 1 bottle of water
5. 10 packets of pencils 6. 1 tin of milk
7. 1 bag of Semolina 8. 1 packet of biscuits
9. 2 big tins of Peak Milk
Standard units of weight
We need to use standard units to measure weight.
The kilogram (kg) is used as a unit when weighing heavy objects like
bags of rice, bags of cement, etc.
The gram (g) is used when weighing lighter objects like pencils, rulers, etc.
Measuring and estimating weight
These are different types of weighing scales
Exercise 2
Classify these objects according to their weight in grams and kilograms.
Name of objects Weight in grams (g) Weight in kilogram (kg)
1. Bottle of water
2. Pencil
3. Eraser
4. Bag of sugar
5. Jug
6. Ruler
7. Stone
8. Bottle of Fanta.182
Name of objects Weight in grams (g) Weight in kilogram (kg)
9. Toothbrush
10. Orange
11. Rock
12. Scissors
13. 5 tins of Milo
14. A bundle of nails
15. 2 notebooks
16. A baby boy
Grams and kilograms
1000 grams (g) = 1 kilogram (kg)
short form short form
We can convert weights in grams to kilograms and weights in kilograms to grams
Examples
2 kg = 1000 g + 1000 g = 2000 g
1/2kg = 1000 g ÷ 2 g = 500 g
2000 g = 2000 g ÷ 1000 g = 2 kg
Exercise 2
A. Answer these.
1. How many kilograms are there in these:
a) 3000 g = b) 2500 g = c) 4000 g =
2. What must I add to 700 g to make 1 kg?
3. How many grams are there in these:
a) 1/2kg = b) 1/4kg = c) 3/4kg =
4. Which is greater?
a) 2000 g or 11/2kg b) 1500 g or 1 kg c) 3500 g or 3 kg
1. Copy and complete the following. Use symbols > or <.
a) 200 g[] 1/4kg b) 2/5kg[] 300 g c) 100 g[] 1/5kg d) 1 kg[] 700 g
e) 900 g[] 3/4kg f) 400 g[] 1/2kg g) 3/5kg[] 1/2kg h) 3/4kg[] 1/2kg
i) 800 g []3/4kg j) 2/5kg[] 1/4kg
2. Copy and complete the following. Use the number line to help you.
a) 1/2kg =[] g b) 3/4kg =[] g c) 1/5kg =[] g d) 1/4kg =[] g e) 2/5kg =[] g f) 1/10 kg =[] g g) 3/5kg =[] g h) 4/5kg =[] g
3. Copy and complete the following. The first one is done for you.
a) 11/2kg =[] 1 kg +[] 12kg
= 1 kg + 500 g
= 1 kg 500 g
c) 31/4kg =[] kg +[] g
=[] kg +[] g
e) 1/15kg =[] 1 kg +[] kg
=[] kg[] g
b) 21/2kg =[] kg +[] 12kg=[] kg{} g
d) 23/5kg ={}| kg +{} g
={} kg {}g
f) 3 1/10 kg =() kg +() g
=() kg() g
