Class: Primary 1
Term: 2nd Term
Week: 6
Age: 6 years
Duration: 45 minutes
Subject: Mathematics
Curriculum Theme: Mathematics
Previous Lesson: Length, the Concept of Length.
Topic: Length
Subject Matter: Value of length, Ordering of length, Units of measurement of length, Recitation of conversion of units

Specific Objectives

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

Cognitive Domain:

Identify the value of length (e.g., long, short).
Identify various standard units of measurement of length such as centimetre (cm) and metre (m).
Recite simple conversion of units (e.g., 100 cm = 1 m; 1000 m = 1 km).
Carry out simple addition and subtraction of lengths.

Affective Domain:

Appreciate the importance of ordering lengths in daily life.
Show interest in measuring objects around them.

Psychomotor Domain:

Use a ruler to measure short lengths in centimetres.
Arrange objects from shortest to longest or longest to shortest.

Work cooperatively in groups to measure and compare lengths of different objects.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum
State Unified Scheme of Work
New General Mathematics for Primary Schools 1

Instructional Materials

The teacher will teach this lesson with the aid of:

Rulers
Measuring tape
Various objects of different lengths (e.g., pencil, book, stick, string)
Chart showing units of length and simple conversions

Rationale for the Lesson

This lesson helps pupils understand the concept of length, which is important for comparing sizes of objects and for practical tasks like measuring materials. It enables them to use standard units of measurement in their everyday activities.

Prerequisite/Previous Knowledge

Pupils can count numbers, identify basic shapes, and compare objects using terms like “big” and “small.”

Lesson Content/Board Summary

Length

Value of Length

Length tells us how long or short an object is. We use words like ‘long’, ‘short’, ‘longer’, ‘shorter’, ‘tall’, ‘small’ to describe the length of things.

Examples:

A pencil is shorter than a stick.
A building is taller than a car.

Ordering of Length

Ordering length means arranging objects based on how long they are. We can order objects from:

Shortest to Longest
Longest to Shortest

Units of Measurement of Length

Units of length help us to measure how long things are accurately.
Some common standard units of measurement for length are:

Centimetre (cm): Used for measuring shorter lengths, like the length of a pencil or a book.
Metre (m): Used for measuring longer lengths, like the height of a door or the length of a classroom.
Kilometre (km): Used for measuring very long distances, like the distance between two towns.

Recitation of Conversion of Units

We can change one unit of length to another. It is important to know these conversions:

100 centimetres (cm) = 1 metre (m)
1000 metres (m) = 1 kilometre (km)

Simple Addition and Subtraction of Lengths

We can add and subtract lengths just like we add and subtract numbers, but we must keep the units the same.

Examples:

1. Addition:

Step 1: Write down the given lengths.

Step 2: Add the numbers.

Step 3: Write the unit with the answer.

Example: 5 cm + 8 cm = ?

Step 1: 5 cm + 8 cm

Step 2: 5 + 8 = 13

Step 3: So, 5 cm + 8 cm = 13 cm

2. Subtraction:

Step 1: Write down the given lengths.

Step 2: Subtract the numbers.

Step 3: Write the unit with the answer.

Example: 10 m – 4 m = ?

Step 1: 10 m – 4 m

Step 2: 10 – 4 = 6

Step 3: So, 10 m – 4 m = 6 m

Teaching Methods/Instructional Techniques

Discussion, Lecture, Demonstration, Question and Answer, Visual Aids

Instructional Procedures

Lesson: Length

Step 1: Introduction

Time: 3 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher greets the pupils and asks them to look at different objects in the classroom (e.g., a pencil, a book, a ruler, a table). The teacher asks which object is longer or shorter.
Pupils’ Activity: Pupils respond to the greetings and point out objects that are longer or shorter.
Learning Point: Pupils recall prior knowledge of comparing sizes of objects.

Step 2: Value of Length

Time: 7 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher explains what length is using real objects. The teacher demonstrates how to compare the length of two objects (e.g., holding a short pencil and a long pencil side-by-side).
Pupils’ Activity: Pupils observe the teacher’s demonstration and identify objects as ‘long’ or ‘short’.
Learning Point: Pupils understand the concept of length and can describe objects using ‘long’ and ‘short’.

Step 3: Ordering of Length

Time: 7 minutes
Teaching Skill: Practical Activity/Group Work
Teacher’s Activity: The teacher gives groups of pupils different objects (e.g., three different lengths of string, three different sized pencils) and instructs them to arrange them from shortest to longest.
Pupils’ Activity: Pupils work in groups to arrange the objects according to their lengths.
Learning Point: Pupils learn to order objects based on their length.

Step 4: Units of Measurement of Length

Time: 7 minutes
Teaching Skill: Explanation/Introduction
Teacher’s Activity: The teacher introduces standard units of length such as centimetre (cm) and metre (m) using a ruler and a measuring tape. The teacher explains what each unit is used for and demonstrates how to measure with a ruler.
Pupils’ Activity: Pupils listen attentively and practice holding a ruler.
Learning Point: Pupils identify standard units of length (cm, m) and understand their use.

Step 5: Recitation of Conversion of Units

Time: 5 minutes
Teaching Skill: Recitation/Memorization
Teacher’s Activity: The teacher writes simple unit conversions on the board (100 cm = 1 m; 1000 m = 1 km) and leads the pupils in reciting them several times.
Pupils’ Activity: Pupils recite the conversion facts after the teacher.
Learning Point: Pupils can recite basic length conversions.

Step 6: Simple Addition and Subtraction of Lengths

Time: 8 minutes
Teaching Skill: Problem Solving/Demonstration
Teacher’s Activity: The teacher writes simple addition and subtraction problems involving lengths (e.g., 5 cm + 8 cm = ?, 10 m – 4 m = ?) on the board and guides pupils through solving them step-by-step.
Pupils’ Activity: Pupils copy the examples and solve similar problems in their notebooks.
Learning Point: Pupils can perform simple addition and subtraction of lengths.

Step 7: Evaluation/Review

Time: 5 minutes
Teaching Skill: Questioning/Assessment
Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

What is length?
Mention two units used to measure length.
Recite the conversion for metres to centimetres.
Solve: 7 cm + 6 cm = ?
Solve: 15 m – 5 m = ?

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 3 minutes
Teaching Skill: Summarization
Teacher’s Activity: The teacher summarizes the lesson by reiterating the meaning of length, its units, ordering, and simple calculations. The teacher gives pupils homework to measure different objects at home using a ruler.
Pupils’ Activity: Pupils listen to the summary and copy the homework.
Learning Point: Pupils consolidate their understanding of length.

Home Task: Solve two new exercises on Length. Show each step and check each answer.

Lesson Keywords

Length – How long or short something is.
Centimetre (cm) – A small unit for measuring length.
Metre (m) – A larger unit for measuring length.
Kilometre (km) – A very large unit for measuring distance.
Measure – To find the size or amount of something.
Ruler – A tool used for measuring short lengths.

Differentiation

For pupils who grasp concepts quickly, the teacher can provide more complex addition and subtraction problems or ask them to measure objects using non-standard units (e.g., hand spans) and then compare with standard units. For pupils needing more support, the teacher will provide extra one-on-one guidance and simpler objects to measure, focusing on identifying long/short and using a ruler correctly.

Note for teachers using this lesson plan

Encourage practical activities throughout the lesson to make the concept of length tangible for Primary 1 pupils. Use a variety of real-life objects for demonstration and practice. Emphasize correct use of the ruler and clear pronunciation of unit names. Ensure all pupils get a chance to measure and compare objects.