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

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

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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

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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

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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 12

14 = 1 x 14, 14 x 1, 2 x 7, 7 x 2

Factors of 14 = 1, 2, 7 and 7

Common 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, 5 and 15

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

Factors of 10 are 1, 2, 5 and 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

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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

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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.

LESSON EVALUATION 

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

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