# Least Common Multiple

Last Updated on July 15, 2020 by Alabi M. S.

MATHEMATICS

SECOND TERM

WEEK 4

PRIMARY 4

TOPIC: LCM

LEARNING AREA

1. Lesson One – Multiples
2. Lesson Two – Common Multiple
3. Lesson Three – Least Common Multiple

TIME – 40 Minutes each.

LEARNING OUTCOME

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

1. find the multiples of numbers up to 9.
2. find common multiple of numbers.
3. find the lowest common multiples by listing the multiples of numbers.
4. find the lowest common multiple by calculation.

RATIONALE

The LCM is the “lowest common multiple” that can be used before fractions can be added, subtracted or compared. The concept of LCM will enable pupils to understand and appreciate common multiple in working out things from various groups.

LEARNING MATERIALS

The teacher will teach the lesson with the aid of chart of multiplication table.

PREVIOUS KNOWLEDGE

1. 2 x 4 = 12
2. 3 x 2 = 5
3. 5 x 4 = 20….

REFERENCE MATERIALS

1. 9 – Years Basic Education Curriculum
2. Lagos State Scheme of work
3. New Method Mathematics Book 6
4. All Relevant Materials
5. Online Materials

LESSON PLAN/DEVELOPMENT

LESSON DEVELOPMENT 1 – MULTIPLE OF NUMBERS Document

STAGE 1 – Introduction (5 minutes)

Teacher’s Activities

1. Guides pupils to read and write multiplication tables.
2. Introduce multiple of numbers with examples – multiple of 2 = 2, 4, 6, 8, 10, 12, etc.

Learner’s Activities

1. 2 x 1 = 2
2. 2 x 2 = 4
3. 2 x 3 = 6
4. 3 x 1 = 3
5. 3 x 2 = 6
6. 3 x 3 = 9,… etc.

Learning Points – Previous Knowledge

STAGE 2 – Grouping (5 minutes)

Teacher’s Activities

1. Groups the pupils into four groups – A, B, C, and D.
2. Guide the pupils to choose a leader and secretary for your group.
3. Gives each group learning materials.

Pupil’s Activities

1. Belong to a group.
2. Choose their leader and secretary.
3. Received learning materials for their group.

Learning Points – Pupil’s group, leader and secretary confirmed

STAGE 3 – Multiple of Numbers (10 minutes)

Teacher’s Activities – Guided instructions:

Guides the pupils through the activities – the multiples of the following numbers are:

1. 2 = 2, 4,…
2. 3 = 3, 6,…
3. 4 = 4, 8,…

Pupil’s Activities

1. 2 = 2, 4, 6, 8, 10, 12, 14,…
2. 3 = 3, 6, 9, 12, 15, 18, 21, 24,…
3. 4 = 4, 8, 12, 16, 20, 24,…

Learning Points – Multiple of Numbers

STAGE 4 – EVALUATION (5 minutes)

Teacher’s Activities

Find the multiples of

1. 5 = 5,…. 30
2. 6 = 6,…. 36
3. 7 = 7,…. 42

Pupil’s Activities

1. 5 = 5, 10, 15, 20, 25, 30.
2. 6 = 6, 12, 18, 24, 30, 36.
3. 7 = 7, 14, 21, 28, 35, 42.

Lesson Points – Lesson Evaluation

STAGE 5 – CONCLUSION (5 minutes)

Teacher’s Activities

1. The first multiple of a number is the number itself.
2. Other multiples are obtained by repeated addition of the number.
3. 2 = 2, 2 + 2, 2 + 2 + 2, 2 + 2 + 2 + 2,… = 2, 4, 6, 8,…

Pupil’s Activities

Learning Points – Conclusion

LESSON DEVELOPMENT 2 – COMMON MULTIPLE document

STAGE 1 –  Introduction (5 minutes)

Teacher’s Activities

Find the multiples of:

1. 2
2. 3
3. 4

Pupil’s Activities

Multiple of:

1. 2 = 2, 4, 6, 8, 10, 12, 14,…
2. 3 = 3, 6, 9, 12, 15, 18, 21, 24,…
3. 4 = 4, 8, 12, 16, 20, 24,…

Learning Points – Previous knowledge confirmed.

STAGE 2 – Grouping (5 minutes)

Teacher’s Activities

1. Groups the pupils into four groups – A, B, C, and D.
2. Guide the pupils to choose a leader and secretary for your group.
3. Gives each group learning materials.

Pupil’s Activities

1. Belong to a group.
2. Choose their leader and secretary.
3. Received learning materials for their group.

Learning Points – Pupil’s group, leader and secretary confirmed

STAGE 3 – Development (20 minutes)

Teacher’s Activities

Lead pupils to understand that the multiplication table can be use to find the multiple of numbers (2 numbers):

1. 2 and 3
2. 2 and 4

Pupil’s Activities

1. Multiple of:

• 2 = 2, 4, 6, 8, 10, 12, 14…
• 3 = 3, 6, 9, 12, 15, 18, 21, 24,…

Common multiple are 6 and 12.

2. Multiple of:

• 2 = 2, 4, ,6 8, 10, 12, 14,…
• 4 = 4, 8, 12, 16, 20, 24,…

Common multiple are 4, 6, 12.

Learning Points – Common multiple

STAGE 4 –  (5 minutes)

Teacher’s Activities

ASSIGNMENT – find the common multiple of:

1. 4 and 6
2. 3 and 6

Pupil’s Activities

1. Assignment taken

STAGE 5 – Conclusion (5 minutes)

Teacher’s Activities

CONCLUSION

Lets pupils to understand that 2 × 3 = 6 and the multiples of 2 and 3 are the multiples of 6.

Pupil’s Activities

LESSON DEVELOPMENT 3 – LEAST COMMON MULTIPLE document

STAGE 1 –  (10 minutes)

Teacher’s Activities

• Find the common multiple of:
1. 4 and 6
2. 3 and 6
• What is the smallest number of the common multiple?
• Introduction the topic – LCM

Pupil’s Activities

1. Multiple 4 and 6 are:

• 4 = 4, 8, 12, 16, 20, 24,…
• 6 = 6, 12, 18, 24, 30, 36,…

Common multiple are 12 and 24.

2. Multiple of 3 and 6 are:

• 3 = 3, 6, 9, 12, 15, 18, 21, 24,…
• 6 = 6, 12, 18, 24, 30, 36,…

Common multiple are 6, 12, 18, and 24.

3. 12 is the smallest of 12 and 24.

4. 6 is the smallest of 6, 12, 18 and 24.

Learning Points – Previous Knowledge and Lesson Introduction.

STAGE 2 – Grouping (5 minutes)

Teacher’s Activities

1. Groups the pupils into four groups – A, B, C, and D.
2. Guide the pupils to choose a leader and secretary for your group.
3. Gives each group learning materials.

Pupil’s Activities

1. Belong to a group.
2. Choose their leader and secretary.
3. Received learning materials for their group.

Learning Points – Pupil’s group, leader and secretary confirmed

STAGE 3 – LCM

Teacher’s Activities

• LCM stands for least common multiple.
• Lets pupils to understand that least means lowest or smaller number of common factors.
• Guides the pupils to find the LCM of:
1. 2 and 3
2. 2 and 4

Pupil’s Activities

1. Multiple of:

• 2 = 2, 4, 6, 8, 10, 12, 14,…
• 3 = 3, 6, 9, 12, 15, 18, 21, 24,…

Common multiple are 6 and 12.

LCM of 6 and 12 is 6.

2. Multiple of:

• 2 = 2, 4, ,6 8, 10, 12, 14,…
• 4 = 4, 8, 12, 16, 20, 24,…

Common multiple are 4, 6, 12.

LCM of 2 and 4 is 4.

Learning Points – Least Common multiple of numbers

STAGE 4 – Assignment (5 minutes)

Teacher’s Activities

ASSIGNMENT – Find the LCM of:

1. 4 and 6
2. 3 and 6

Pupil’s Activities

• Assignment taken

STAGE 5 – Conclusion (5 minutes)

Teacher Activities

To conclude the lesson for the week, the teacher revises (through questions and answers) the entire lesson and links it to the next lesson.

Pupil’s Activities