The 11 Times Trick

We all know the trick when multiplying by ten – add 0 to the end of the number, but did you know there is an equally easy trick for multiplying a two digit number by 11? This is it:

Take the original number and imagine a space between the two digits (in this example we will use 52:

If the numbers in the middle add up to a 2 digit number, just insert the second number and add 1 to the first:

We all know the trick when multiplying by ten – add 0 to the end of the number, but did you know there is an equally easy trick for multiplying a two digit number by 11? This is it:

Take the original number and imagine a space between the two digits (in this example we will use 52:

**5_2**

**Now add the two numbers together and put them in the middle:**

**5_(5+2)_2**

**That is it – you have the answer: 572.**

**9_(9+9)_9**

**(9+1)_8_9**

**10_8_9**

**1089**– It works every time.