# Factors of number and HCF of 2 – digit Numbers (Primary 4)

Last Updated on July 16, 2020 by Alabi M. S.

**MATHEMATICS **

**SECOND TERM** ** **

**PRIMARY 4**

**THEME – **

**PREVIOUS LESSON – Second Term Scheme of Work and Plan Lesson Notes for MATHEMATICS Week 1 to Week 12 Primary Schools**

**TOPIC – FACTORS OF NUMBERS AND HCF OF 2 – DIGIT NUMBERS **

**LEARNING AREA**

1. Factors of Number

2. HCF of 2 – digit Numbers

**PERFORMANCE OBJECTIVES **

By the end of the lesson, the pupils should have attained the following objectives (cognitive, affective and psychomotor) and should be able to find the HCF of 2-digit numbers.

**ENTRY BEHAVIOUR**

**INSTRUCTIONAL MATERIALS**

The teacher will teach the lesson with the aid of:

1. Flannel Board

2. Flash card

3. Number cards

**METHOD OF TEACHING – Choose a suitable and appropriate methods for the lessons.**

*Note – Irrespective of choosing methods of teaching, always introduce an activities that will arouse pupil’s interest or lead them to the lessons. *

**REFERENCE MATERIALS**

1. Scheme of Work

2. 9 – Years Basic Education Curriculum

3. Course Book

4. All Relevant Material

5. Online Information

**CONTENT OF THE LESSON **** **

## LESSON ONE – INTRODUCTION TO FACTORS OF NUMBER

Pupil’s Activities 1 – Express Number as A Product of Two Numbers

**Sample – Quantitative Reasoning **

1 = 1 x 1

2 = 1 x 2, 2 x 1

3 = 1 x 3, 3 x 1

4 = 1 x 4, 4 x 1, 2 x 2

6 = 1 x 6, 6 x 1, 2 x 3, 3 x 2

**Express the number – 5, 7, 8, 9 and 10 as product of two numbers. **

**Expected response **

1. 5 = 1 x 5, 5 x 1

2. 7 = 1 x 7, 7 x 1

3. 8 = 1 x 8, 8 x 1, 4 x 2, 2 x 4

4. 9 = 1 x 9, 9 x 1, 3 x 3

5. 10 = 1 x 10, 10 x 1, 2 x 5, 5 x 2

**Teacher’s remark – Each digit of the product of a number is a factor that number. For example, 1 and 5 are factors of 5 without repeating any number. Also, 1, 2, 4 and 8 are the products of 8, 1, 2, 5, and 10 are factors of 10.**

Pupil’s Activities 2 – Exercises/Take Home

Find the factors of

1. 11

2. 12

3. 13

4. 14

5. 15

## LESSON TWO – COMMON FACTORS OF NUMBERS

Teacher’s/Pupil’s Activities 1 – Marking and Correction

*Note – Prepare a multiplication table and guide pupils on how to use the table as they find the product of numbers. *

Find the factors of

1. 11 = 1 x 11, 11 x 1

Factors of 11 = 1 and 11

2. 12 = 1 x 12, 12 x 1, 2 x 6, 6 x 2, 4 x 3, 3 x 4

Factors of 12 = 1, 2, 3, 4, 6 and 12

3. 13 = 1 x 13, 13 x 1

Factors of 13 are 1 and 13

4. 14 = 1 x 14, 14 x 1, 2 x 7, 7 x 2

Factors of 14 = 1, 2, 7 and 7

5. 15 = 1 x 15, 15 x 1, 3 x 5, 5 x 3

Factors of 15 = 1, 3, 5 and 15.

Pupil’s Activities 2 – Common Factors of 2 or More Numbers

Find the common factors between

1. 12 and 14

12 = 1 x 12, 12 x 1, 2 x 6, 6 x 2, 4 x 3, 3 x 4

Factors of 12 =

1,2, 3, 4, 6 and 1214 = 1 x 14, 14 x 1, 2 x 7, 7 x 2

Factors of 14 =

1,2, 7 and 7Common Factors are 1 and 2

2. 15 and 10

15 = 1 x 15, 15 x 1, 3 x 5, 5 x 3

Factors of 15 are

1, 3,5and 1510 = 1 x 10, 10 x 1, 2 x 5, 5 x 2

Factors of 10 are

1, 2,5and 10.Common factors are 1 and 5

Pupil’s Activities 3 – Highest Common Factors

Mark out the highest numbers in 1, 5, 3, 2 and 0.

The highest is

5

Teacher’s remark – The HCF of numbers is the highest common factor.

Find the HCF of

1. 12 and 14

Factors of 12 = 1, 2, 3, 4, 6 and 12

Factors of 14 = 1, 2, 7 and 7

Common Factors are 1 and 2

HCF is 2.

2. 10 and 15

Factors of 15 are 1, 3, 5 and 15

Factors of 10 are 1, 2, 5 and 10.

Common factors are 1 and 5

HCF is 5.

Pupil’s Activities 3 – Exercises/Take Home

Find the HCF of

1. 12 and 18

2. 16 and 24

3. 15 and 20

4. 10 and 20

## LESSON THREE – HCF BY CALCULATION

Teacher’s/Pupil’s Activities 1 – HCF by Calculation

Find the HCF of

1. 14 and 28

Therefore,

HCF is 2 x 7 = 14

2. 16 and 24

Therefore,

HCF is 2 x 2 x 2 = 8

Pupil’s Activities 2 – HCF Using Factors Methods to Confirm Activities 1

HCF of 14 and 28

Products of 14

1 x 14

14 x 1

2 x 7

7 x 2

Factors of 14 are 1, 2, 7 and 14

Products of 28

1 x 28

28 x 1

2 x 14

14 x 2

4 x 7

7 x 4

Factors of 24 are 1, 2, 7, 14 and 28.

Common Factors 14 and 28 are 1, 2, 7 and 14

HCF of 14 and 28 is 14

**Use the same procedure to confirm HCF of 16 and 24**

**Pupil’s Activities 3 – Exercises/Take Home **

Find the HCF using calculation,

1. 12 and 36

2. 15 and 36

3. 25 and 15

4. 16 and 48

**PRESENTATION**

To deliver the lesson, the teacher adopts the following steps:

1. To introduce the lesson, the teacher revises the previous lesson. Based on this, he/she asks the pupils some questions;

2. Guides pupils to use flannel board and flash cards to identify HCF numbers.

Pupil’s Activities – Use flannel board and flash cards to identify common factors of given numbers.

3. Finds the HCF of two digit numbers.

Pupil’s Activities – Find the HCF of two digit numbers.

**CONCLUSION**

- To conclude the lesson for the week, the teacher revises the entire lesson and links it to the following week’s lesson.

- Next Lesson –
**Second Term Scheme of Work and Plan Lesson Notes for MATHEMATICS Week 1 to Week 12 Primary Schools**

**LESSON EVALUATION **

**Pupils to find the common factors of given numbers and hence determine the HCF.**