# Addition of Whole Numbers with the Sum less than 40 (Primary 1)

**MATHEMATICS **

**SECOND TERM** ** **

**PRIMARY 1**

**THEME – BASIC OPERATIONS **

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

**TOPIC – ADDITION OF WHOLE NUMBERS WITH THE SUM LESS THAN 40**

**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 add two whole numbers with the results from 20 to 19 and sum less than 40

**ENTRY BEHAVIOUR**

Addition of numbers or objects

**INSTRUCTIONAL MATERIALS**

The teacher will teach the lesson with the aid of:

1. Oranges

2. Balls

3. Leaves

4. Bottle tops

5. Number beads, etc.

**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 **

Pupil’s Activities 1 – Introduction to Expansion of Numbers

Quantitative Reasoning (Oral)

Sample

10 = 10 + 0

12 = 10 + 1

21 = 20 + 1

36 = 30 + 6

Expand

1. 15 = ____ + ____

2. 34 = ____ + ____

3. 19 = ____ + ____

4. 39 = ____ + ____

Teacher’s/Pupil’s Activities 2 – Using Expansion of Numbers in Addition

Working Examples

1. 5 + 12 = 10 + 5 + 10 + 2

= 10 + 10 + 5 + 2

= 20 + 7

= 27.

2. 25 + 15 = 20 + 5 + 10 + 5

= 20 + 10 + 5 + 5

= 30 + 10

= 40

Pupil’s Activities 3 – Exercise/Take Home

Copy and complete,

1. 15 + 23 = ____ + ____ + ____ + ____

= ____ + ____ + ____ + ____

= ____ + ____

= ____

2. 25 + 11 = ____ + ____ + ____ + ____

= ____ + ____ + ____ + ____

= ____ + ____

= ____

3. 18 + 21 = ____ + ____ + ____ + ____

= ____ + ____ + ____ + ____

= ____ + ____

= ____

4. 23 + 17 = ____ + ____ + ____ + ____

= ____ + ____ + ____ + ____

= ____ + ____

= ____

**LESSON TWO – Continue the activities in lesson one **

**LESSON THREE – USING VERTICAL/COLUMN METHOD **

Pupil’s Activities 1 – Arrange the Numbers under Tens and Units

Quantitative Reasoning,

Sample

23 = 20 + 3 = Tens + Units

T U

2 3

37 = 30 + 7 = Tens + Units

T U

3 7

Arrange under Tens and Units

1. 18

2. 34

**Teacher’s/Pupil’s Activities 2 – Arrange the Numbers under Tens and Units Easy Addition **

Working Examples

1. 14 + 22

T U

/ 1 4 ////

+ // 2 2 //

________

3 6

2. 11 + 26

T U

/ 1 1 /

+ // 2 6 /////

_________

3 7

Pupil’s Activities 3 – Exercise/Take Home

Copy and complete the following using the vertical/column method.

1. 15 + 22

2. 25 + 13

3. 18 + 11

4. 16 + 13

**LESSON FOUR – continue the activities in Lesson 3 **

**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 group the objects into ones, twos, threes and fours to form sum less than 40 e.g. 17 balls and 15 balls give 32 balls.

Pupil’s Activities – Group objects into ones, twos, threes and fours to form sums less than 40 and count the total.

**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 **add given whole numbers.