Subject: Mathematics

Topic: Multiplication of Decimals by Whole Numbers

Duration: 40mins/period

Reference Material: Macmillan Champion Mathematics, 5

Previous Knowledge: Pupils are familiar with multiplication.

Objective: At the end of the lesson, pupils should:

  1. Multiply decimals by 10, 100 and 1000
  2. 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.