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:

1. add and subtract three 4-digit whole numbers;
2. add and subtract decimals;
3. identify mixed numbers and improper fractions;
4. solve mixed operation problems on addition and subtraction;
5. 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:

1. Flash card of whole numbers
2. Flash card of decimals
3. Flash card fractions

METHOD OF TEACHING

1. Explanation
2. Discussion
3. Demonstration
4. Questions and answers

REFERENCE MATERIALS

1. Scheme of Work
2. 9 – Years Basic Education Curriculum
3. New Method Mathematics Book 6
4. All Relevant Material
5. 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:

1. 8 7 6 9 + 8 7 2 4 + 6 4 5 4
2. 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

1. Solve 9 0 4 7 6 2 – 9 9 9 9 9 9 + 6 2 8 8 0 4
2. 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:

1. 2 2/7 =
2. 3 3/8 =

Convert improper fraction to a mixed number:

1. 23/4 =
2. 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. 

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CULTURAL AND CREATIVE ART Plan Lesson Note Week 8

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 solve problems involving addition and subtraction of whole numbers, fractions and decimals;
3. 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.