PRIMARY 6: MATHEMATICS – SECOND TERM | WEEK 8

TOPIC: WEIGHT

A: TEACHING AND LEARNING MATERIALS

1. Weighing scale.
2. Balance scale.
3. Bags of rice or beans.
4. Small classroom objects.
5. Weight conversion chart.
6. Pupils’ exercise books and pencils.

B: REFERENCE MATERIALS

1. Scheme of work.
2. Recommended Mathematics textbook for Primary 6.
3. Online educational resources.

C: PREVIOUS KNOWLEDGE

The pupils have learnt measurement and can use standard units to measure length, volume and capacity.

D: PERFORMANCE OBJECTIVES

By the end of the lesson, pupils should be able to:

1. Explain the meaning of weight.
2. State the common units of weight.
3. Convert grams to kilograms.
4. Convert kilograms to grams.
5. Convert kilograms to tonnes.
6. Add and subtract weights.
7. Multiply and divide weights.
8. Solve simple word problems involving weight.

E: CONTENT

Meaning of Weight

Weight tells us how heavy or light an object is.
Examples:
⚖️ A pencil is light.
⚖️ A bag of rice is heavier.

Units of Weight

Common units of weight are:

• gram (g)
• kilogram (kg)
• tonne (t)

The relationships are:

1,000 g = 1 kg

1,000 kg = 1 tonne

Converting Kilograms to Grams

Multiply by 1,000.
Example:

5 kg = 5 × 1,000 = 5,000 g

Converting Grams to Kilograms

Divide by 1,000.
Example:

4,000 g = 4 kg

Converting Tonnes to Kilograms

Example:

3 tonnes = 3 × 1,000 = 3,000 kg

Addition of Weight

3 kg 200 g + 2 kg 500 g
\= 5 kg 700 g

Subtraction of Weight

8 kg − 3 kg
\= 5 kg

Multiplication of Weight

One bag weighs 5 kg.
Six bags weigh:
5 kg × 6 = 30 kg

Word Problem

A trader has 50 kg of rice and sells 18 kg.
Weight remaining:
50 kg − 18 kg = 32 kg

F: LESSON PRESENTATION

F1: Teachers’ Activities

1. Introduces weight using classroom objects.
2. Shows pupils a weighing scale.
3. Explains grams, kilograms and tonnes.
4. Demonstrates conversion between units.
5. Demonstrates addition and subtraction of weights.
6. Guides pupils in multiplying and dividing weights.
7. Gives simple word problems.

F2: Pupils’ Activities

1. Identify light and heavy objects.
2. State units of weight.
3. Measure the weight of simple objects.
4. Convert grams to kilograms.
5. Convert kilograms to grams.
6. Add and subtract weights.
7. Solve simple weight problems.

G: CONCLUSION

The teacher revises the units of weight and their relationships.
The teacher corrects pupils where necessary and reminds them to use the correct unit when stating the weight of an object.

H: EVALUATION GUIDE

Pupils should be able to answer the following questions:

1. What is weight?
2. State three units of weight.
3. How many grams make 1 kilogram?
4. How many kilograms make 1 tonne?
5. Convert 6 kg to grams.
6. Convert 5,000 g to kilograms.
7. Convert 2 tonnes to kilograms.
8. A bag weighs 10 kg. What is the weight of 5 such bags?