Page 1 - Lesson Note 5

Subject – Mathematics

Chapter 2 – OPERATION ON LARGE NUMBERS

Sub-topic-5:- MULTIPLICATION BY 3 DIGIT and 4 DIGIT NUMBER

Multiplication of 3-digit numbers by 3-digit numbers:

Step 1: Arrange the numbers both multiplicand and multiplier column wise.

Step 2: First we have to multiply the multiplicand by ones digit of the multiplier, and write
the product at the line below. If you are getting a more than one digit number than
regroup the number.

Step 3: Multiply the multiplicand by the digit at the tens of the multiplier, but place a zero
or put cross in the ones place column, since this part of the multiplication is a number of
tens. If you are getting a more than one digit number than regroup the number.

Step 4: Multiply the multiplicand by the digit at the hundreds of the multiplier, but place
a zero or cross at the ones and tens place column, since this part of the multiplication is
a number of hundred. If you are getting a more than one digit number than regroup the
number.

Step 5: Now add all product.

Step 6: The final result of the multiplication we will get.

Example 1:5 0 2 x 3 3 6

Step 1:Arrange the number columnwise

Step 2: Multiply 502 by 6 and write the result on the line below.

Note: while multiplying 6 by 2ones we get 12ones = 1 tens + 2 ones. Write 2 in ones
column and carry over 1. Multiply 6 x 0tens = 0 tens + 1 tens (carry over) = 1 tens, now
write 1next to 2. No number is to carry over to the next place. Now, multiply 6 x
5hundreds = 30 hundred. Write the number in the hundred column. So the number is 30
H + 1T + 2O =3012.