Lesson 4 – Multiplying Two Digit Numbers By Two Digit Number.

Objective:

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

Example 1

Multiply 43 by 12

Solution

Multiply 43 by 2 to get 86. Write 6 in the units column and and the 4 in the tens column. Multiply 43 by 1, write the 3 under the tens column and 4 under the hundreds column. You add up the two products in the order in which they appear. The answer becomes 516.

Example 2

Multiply 57 by 32.

Solution

With your knowledge in multiplying a two digit number by one digit number, you can easily multiply a two digit number by a two digit number.

52 x 2 = 114

Always write zero under the 4 in the units column. Since 3 is in the tens column when you multiply it by 7 units, you will get 21 tens. Write 1 under the tens column and carry 2 forward to the hundreds column.

3 tens times 5 tens gives 15 hundreds plus the 2 you carried forward gives 17 hundred. This is 1 thousand and 7 hundreds.

57 x 3 tens = 1710

1710 should be arranged orderly. After that, you add the two products to get 1824.

Your answer becomes 1824.