Multiplying any 3-digit numbers between 100 and 109

Multiplying any 3-digit numbers between 100 and 109 together is a 3-step simple technique:

Step 1:     Put 1 as the first digit of the answer. It will always be 1.

Step 2:   Add the last digits of each numbers. That’s the next two digits of the answer. If the addition results in a single digit number, make sure to put an extra zero before it.

Step 3:  Multiply the last digits of each number. That’s the last two digits of the answer. Here also make sure to put an extra zero if the product is a single digit number.

Example: 107 x 105 =?

    107

X  105

      ?

1. The first number will always be 1

     107

 x  105 

1####   (1x1 = 1)

2. Add the last digits of each numbers. 7+5=12. That’s the next two digits of the answer.

      107

  x  105 

 112##   (5+7 = 12)

3. Lastly, multiply the last digits of each number, 7x5=35

      107

 x   105 

 11,235   (5x7 = 35)

The answer is 11,235.

So, 107 x 105 = 11,235

 

Another Example:

108 × 109 = 11,772

And, 103 × 106 = 10,918