Multiply by 11

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Ok so most people know the eleven times table up to 11 x 11, maybe even a couple more.
What about if you need to do 11 x a higher number, here is a quick trick:
 
11 x 18 - the first digit is 1 (from 18), the last digit is 8 (from 18), the middle digit is 1 + 8 (from 18) = 9, the result is 198
Here are some more:
11 x 24 = 2(6)4 = 264
11 x 27 = 2(9)7 = 297
11 x 35 = 3(8)5 = 385
 
If the middle number gets into double digits, simply carry the tens:
11 x 39 = 3(12)9 = 429
11 x 56 = 5(11)6 = 616
11 x 156 = 1(6)(11)6 = 1716
 
A nice easy way to multiply by 11