Let’s begin with one of the favorite feats of mental math – how to multiply, in your head, any 2-digit number by eleven. It’s very easy once you know the secret. Consider the problem:
32 X 11
To solve this problem, simply add the digits, 3 + 2 = 5, put the 5 between 3 and the 2, and there is your answer:
352
What could be easier? Now you try:
53 X 11
Since 5 + 3 = 8, your answer is simply
583
One more. Without looking at the answer or writing anything down, what is
81 x 11?
Did you get 891? Congratulations!
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