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

X       109

    11,772