# Subtraction of Whole Numbers without Exchanging or Remaining (Primary 3)

**MATHEMATICS **

**FIRST TERM** ** **

**WEEK 10**

**PRIMARY 3**

**THEME – WHOLE NUMBERS **

**PREVIOUS LESSON – Addition of 2 or 3 Digit Numbers using the Partial Sums Method (Primary 3)**

**TOPIC – SUBTRACTION OF WHOLE NUMBERS **

**LEARNING AREA**

1. Introductory Activities

2. Subtraction of Whole without Exchanging or Remaining – Expanded and Direct Methods

3. Word Problems on Subtraction of Whole 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 –

1. subtract 2 – digit Whole numbers without exchanging or renaming.

2. subtract 3 – digit whole numbers without exchanging or remaining.

**ENTRY BEHAVIOUR**

Subtraction of Whole Numbers

**INSTRUCTIONAL MATERIALS**

The teacher will teach the lesson with the aid of:

Charts and flash cards, etc. Subtraction cards, Counters, charts, Abacus, 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 – INTRODUCTORY ACTIVITIES **

**REVISION ON SUBTRACTION OF 2 DIGIT WHOLE NUMBERS (10 minutes) **

Teacher’s/Pupil’s Activities – Guides pupils on oral subtraction using subtraction cards. Flash the subtraction cards to the pupils and let them respond by giving correct answers to questions such as 5 – 8, 7 – 4, 6 – 5, etc. contained in addition cards.

Quick Guide and Evaluation on two digit numbers –

1. 2 5 – 1 1

2. 3 6 – 2 2

Solutions 1 – Expanded Method2 5 = 20 + 5

– 1 1 = – (10 + 1)

_______________________________

1 4 = 10 + 4

_______________________________

Therefore, 2 5 – 1 1 = 1 4

Solutions 23 6 = 30 + 6

– 2 2 = – (20 + 2)

_______________________________

1 4 = 10 + 4

_______________________________

Therefore, 3 6 – 2 2 = 1 4

Be sure that the pupils arrange each digit of the numbers correctly. Allow simple counting because of individual difference.

Quick AssessmentFind the answers to these subtraction problems using the expanded form.

1. 5 5 – 3 4

2. 7 6 – 1 2

**ADDITION OF 3 DIGIT WHOLE NUMBERS (10 minutes) **

Teacher’s/Pupil’s Activities – Guides the pupils to add 3 – digit numbers using expanded method.

Working Examples1. 3 2 5 – 1 1 1

2. 5 2 5 – 3 2 5

Solution 1 – Expanded Method3 2 5 = 300 + 20 + 5

– 1 1 1 = – (100 + 10 + 1)

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2 1 4 = 200 + 10 + 4

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Solution 2 – Expanded Method5 2 5 = 500 + 20 + 5

– 3 2 5 = – (300 + 20 + 5)

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2 0 0 = 200 + 00 + 0

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**LESSON EVALUATION/ASSIGNMENT/MARKING/CORRECTION (20 minutes) **

1. 5 3 1 – 3 2 0

2. 3 4 5 – 2 0 4

3. 3 6 5 – 1 1 1

**LESSON TWO – SUBTRACTION OF WHOLE NUMBERS DIRECT METHOD**

Teacher’s/Pupil’s Activities – Guides the pupils to subtract 3 – digit numbers using direct method.

Working Examples1. 3 2 5 – 1 1 1

2. 5 2 5 – 3 2 5

Solution 1

3 2 5 – 1 1 13 2 5

– 1 1 1

___________

2 1 1

___________

Solution 25 2 5 – 3 2 5

5 2 5

+ 3 2 5

___________

2 0 0

___________

**LESSON EVALUATION/ASSIGNMENT/MARKING/CORRECTION (20 minutes) **

1. 5 3 1 – 3 2 0

2. 3 4 5 – 2 0 4

3. 3 6 5 – 1 1 1

**LESSON THREE – ****WORKBOOK – WEEKLY ASSESSMENT **

**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. Teacher’s/Pupil’s Activities – Guides pupils on oral subtraction using subtraction cards. Flash the subtraction cards to the pupils and let them respond by giving correct answers to questions such as 5 – 8, 7 – 4, 6 – 5, etc. contained in addition cards.

3. Guides pupils to subtract two numbers without 3 – digits that involves exchanging or renaming.

Pupil’s Activities – Subtract two numbers without 3 – digits that involve renaming or exchanging.

4. Guides pupils in solving some subtraction problems on the board.

Pupil’s Activities – Solving some subtraction problems on the board.

5. Guides pupils on the use of abacus in subtracting numbers.

Pupil’s Activities – Use abacus to perform subtraction of two numbers without 3- digits.

Workbook – Weekly Assessment

**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:**

1. subtract 2 – digit numbers without exchanging and renaming.

2. subtract two given 3 – digits numbers without exchanging.