You can easily multiply two numbers between 11 and 19 in your head using this method. 
For example, you want to find what 14 x 15 equals... 
Take the number 14 and the second digit of the second number, i.e. 5 and add them together. 
This gives 19. 
Now stick a zero at the end of that, so it becomes 190. 
Remember that number. 
Now take the second digit from each number, i.e. 4 and 5, and multiply them together to give 20. 
Add this number to the number you calculated in the previous step, i.e. 20+190, and you get 210
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