# Addition and Substation of Whole Numbers, Fractions and Decimals

**MATHEMATICS**

**FIRST TERM**

**EIGHTH WEEK**

**BASIC 6**

**THEME: BASIC OPERATION **

**TOPIC: **Addition and subtraction of Whole Numbers, Decimals and fractions

**PERFORMANCE OBJECTIVES**

- By the end of the lesson, the pupils should have attained the following objectives (cognitive, affective and psychomotor) and be able to:

- add and subtract three 4-digit whole numbers;
- add and subtract decimals;
- identify mixed numbers and improper fractions;
- solve mixed operation problems on addition and subtraction;
- solve word problems on addition and subtraction of whole numbers, decimal and fractions.

**ENTRY BEHAVIOR**

The pupils are required to already have learned basic operation on addition and subtraction.

**INSTRUCTIONAL MATERIALS**

The teacher will teach the lesson with the aid of:

- Flash card of whole numbers
- Flash card of decimals
- Flash card fractions

**METHOD OF TEACHING**

- Explanation
- Discussion
- Demonstration
- Questions and answers

**REFERENCE MATERIALS**

- Scheme of Work
- 9 – Years Basic Education Curriculum
- New Method Mathematics Book 6
- All Relevant Material
- Online Information

**CONTENT OF THE LESSON**

**LESSON ONE **

**ADDITION AND SUBTRACTION OF THREE 4-DIGIT WHOLE NUMBERS**

**Example 1.**

5 4 6 8

+ 8 6 5 4

+ 1 6 8 7

_________

1 5 8 0 9

**Example 2**

9 3 2 3

– 5 1 4 7

_________

4 1 7 6

*Lead the pupils to realise that when adding three (4-digit numbers) add the first two numbers together and then add the third to get the total.
*

**Exercises**

Solve the following:

- 8 7 6 9 + 8 7 2 4 + 6 4 5 4
- 9 4 7 2 – 5 8 7 1

**LESSON TWO **

**MIXED OPERATIONS OF ADDITION AND SUBTRACTION**

**Example 1**

Solve, 3 1 8 1 6 4 – 1 0 0 5 8 7 + 2 0 5 2 8 9

**BODMAS** – Addition cones before subtraction

3 1 8 1 6 4

+ 2 0 5 2 8 9

____________

5 1 3 4 5 3

– 1 0 0 2 5 8

____________

4 1 3 1 9 5

Therefore, 3 1 8 1 6 4 – 1 0 0 5 8 7 + 2 0 5 2 8 9 = 4 1 3 1 9 5.

**Example 2 – Problem Solving **

The sum of three numbers is 9 6 3 0 2. Two of them are 3 7 0 2 2 and 3 9 1 8 4. Find the third number.

A + B + C = D,

D – (A + B) = C

First, add the other two numbers.

3 7 0 2 2

+ 3 9 1 8 4

____________

7 6 2 0 6

Then, subtract the result – 7 6 2 0 6 from 9 6 3 0 2.

9 6 3 0 2

– 7 6 2 0 6

____________

2 0 0 9 4

**Exercises**

- Solve 9 0 4 7 6 2 – 9 9 9 9 9 9 + 6 2 8 8 0 4
- What must be subtracted from 1 2 0 9 0 to get 9 8 4 6.

*Guide pupils through this exercise as a class exercise. Assist the pupils if they are having problems in solving.
*

**LESSON THREE**

**MIXED NUMBERS AND IMPROPER FRACTIONS **

Improper fraction: The numerator is greater than the denominator.

Mixed fraction: e.g. 1 5/6, 2 7/9, etc.

Explain the types of fractions to pupils.

**Convert mixed number to improper fraction:**

- 1 5/6 = 11/6
- 2 7/9 = 25/9

**Improper fraction to a mixed number:**

- 19/3 = 6 1/3
- 37/12 = 3 1/12

**Exercises**

Convert mixed number to improper fraction:

- 2 2/7 =
- 3 3/8 =

Convert improper fraction to a mixed number:

- 23/4 =
- 31/8 =

**LESSON FOUR **

**ADDITION AND SUBTRACTION OF MIXED NUMBERS **

Example 1

- 1 2/3 + 1 3/4

= 1 + 2/3 + 1 + 3/4 (rewrite the mixed numbers as whole numbers and fractions)

= 1 + 1 + 2/3 + 3/4

= 2 + 8/12 + 9/12 (change each fraction to equivalent fraction with the same denominator)

= 2 +17/12

= 2 + 1 + 5/12

= 3 + 5/12

= 3 5/12.

- 3 3/8 – 1 1/2

= 3 – 1 + 3/8 – 1/2

= 2 – 3/8 – 4/8

= 1 (8 + 3 – 4)/8

= 1 9/8

= 1 + 1 1/8

= 1 + 1 + 1/8

= 2 1/8.

**Exercises **

Solve

- 1 3/4 + 1 5/8
- 5 1/3 – 2 3/4
- 1 2/5 + 2 7/10 + 1 9/10

**LESSON FIVE **

**ADDITION AND SUBSTATION OF DECIMALS **

**Examples**

- 3 5 . 4 1 + 7 3 . 6 1 4

3 5 . 4 1 0

+ 7 3 . 6 1 4

____________

1 1 9 . 0 2 4

- 7 3 . 6 1 – 3 5 . 4 1 6

7 3 . 6 1 0

– 3 5 . 4 1 6

____________

3 8 . 1 9 4

**Exercises**

- 1 4 1 . 7 6 + 9 0 3 . 4 1 6
- 3 0 3 . 6 5 – 1 4 1 . 6 7 2

**Further exercises **

*As stated in the recommended books. *

**Click to Download… **

**CULTURAL AND CREATIVE ART Plan Lesson Note Week 8**

**PRESENTATION**

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

- To introduce the lesson, the teacher revises the previous lesson. Based on this, he/she asks the pupils some questions;
- Guides pupils to solve problems involving addition and subtraction of whole numbers, fractions and decimals;
- Pupil’s Activities – Solve problems involving addition and subtraction of whole numbers, fractions and decimals.

**CONCLUSION**

- To conclude the lesson for the week, the teacher revises the entire lesson and links it to the following week’s lesson – multiplication of whole numbers and decimals.

**LESSON EVALUATION**

**Pupils to: **solve given problems on addition and subtraction of whole numbers, fractions and decimals.