TOPIC: MEASUREMENT OF LENGTH
A: TEACHING AND LEARNING MATERIALS
- Ruler.
- Metre rule.
- Measuring tape.
- Classroom objects.
- Pupils’ writing books and pencils.
B: REFERENCE MATERIALS
- Scheme of work.
- Recommended Mathematics textbook for Primary 3.
- Online educational resources.
C: PREVIOUS KNOWLEDGE
The pupils have compared objects using words such as long, short, tall and small.
D: PERFORMANCE OBJECTIVES
By the end of the lesson, pupils should be able to:
- Explain the meaning of length.
- Compare the lengths of objects.
- Estimate the length of simple objects.
- Measure objects using non-standard units.
- Measure length in centimetres and metres.
E: CONTENT
Meaning of Length
Length is the distance from one end of an object to the other end.
We can describe objects as:
- long
- short
- longer
- shorter
Example:
📏 A ruler is longer than an eraser.
✏️ A pencil may be shorter than a desk.
Non-Standard Units of Length
We can measure length using:
- handspan ✋
- footsteps 👣
- arm length
- sticks
These are called non-standard units.
Standard Units of Length
The common standard units are:
- centimetre (cm)
- metre (m)
We use a ruler to measure small objects in centimetres.
Examples:
- Pencil – 15 cm
- Book – 25 cm
We use a metre rule or measuring tape for longer objects.
Example:
A classroom door may be about 2 metres high.
F: LESSON PRESENTATION
F1: Teachers’ Activities
- Introduces the meaning of length.
- Shows pupils objects of different lengths.
- Guides pupils to compare long and short objects.
- Demonstrates measurement using handspan and footsteps.
- Introduces centimetres and metres.
- Guides pupils to measure classroom objects.
F2: Pupils’ Activities
- Identify long and short objects.
- Compare the lengths of objects.
- Measure objects using handspan.
- Measure distances using footsteps.
- Use rulers to measure simple objects.
- Record their measurements.
G: CONCLUSION
The teacher revises the meaning and measurement of length and corrects pupils where necessary.
The teacher encourages pupils to practise measuring simple objects around them.
H: EVALUATION GUIDE
Pupils should be able to answer the following questions:
- What is length?
- Mention two non-standard units of length.
- What instrument is used to measure a pencil?
- Which unit is suitable for measuring a book: cm or m?
- Which unit is suitable for measuring the length of a classroom: cm or m?
- Mention two instruments used for measuring length.
- Measure the length of your pencil in centimetres.