Topic: Multiplication of Decimals by Whole Numbers
Reference Material: Macmillan Champion Mathematics, 5
Previous Knowledge: Pupils are familiar with multiplication.
Objective: At the end of the lesson, pupils should:
- Multiply decimals by 10, 100 and 1000
- Solve word problems on multiplication of decimals by whole numbers
Example 1: Multiply 3.8 x 10 =
The decimal points moves one place to the right
Example 2: Multiply 2.74 x 100 = 274
When multiplied by 100, the decimal point is moved two places to the right
Example 3: 3.8 x 1000 = 3800
When we multiply by 1000, the decimal point is moved three places to the right
Step 1: Teacher revises the previous lessons with the pupils
Step 2: Teacher introduces and solve examples on the new topic
Step 3: Pupils are allowed to ask questions
Step 4: Teacher writes questions on multiplication of decimals by whole number on the board for pupils to solve.
(a) 56.9 x 57 (b) 75.9 x 86 (c) 7.324 x 41 (d) 36.8 x 35
(e) The weekly salary of a worker is N850.75. Find his monthly salary.
(f) If 1 packet of biscuits cost N685.50. Find the costs of 80 similar packets.
Conclusion: Teacher moves round for inspection, marking and correction of notes where necessary
Assignment: Page 86, Ex 2, 1 – 5.
Page 88, 1 – 5.