Lesson 7 – Multiplying 2 Digits By 2 Digit Numbers

Objective:

• At the end of this lesson, students should be able to multiply two digit numbers by two digit numbers.

First let’s look at multiplying numbers by multiples of 10.

Examples:

15 x 10 = 150                      16 x 100 = 1600

25 x 10 = 250                      20 x 100 = 2000

From the examples above, we multiply the number with 10 by attaching 0 (zero) and by 100 by attaching 2 zeros. If we are multiplying by thousand (1000) then we will attach 3 zeros.

Examples:

15 x 20 = 300

26 x 30 = 780

From the example above, we can multiply the numbers by multiplying 15 by 2 and then attaching 0 to the answer.

=>       15 x 2 = 30   attach “0” to make it 300.

Please remember that the zero being attached is not done in the normal addition method e.g. 30 + 0 = 30