I always get stuck when I try and multiply 11 with another two digit number. I can do the first nine multiples because you just write the same number twice. Like 2 x 11 = 22 all the way to 9 x 11=99. But multiplying it with a double digit number is another story until I came across this secret strategy that I’ll share with you. For example:
12 x 11 will be 1+2=3
Insert the 3 between the 1 and 2: the answer is 132!
Or 14 x 11 will 1+4=5
Insert 5 between 1 and 4 : answer is 154!
And if the two digits also add up to a two digit number, insert the second and add the first. For example:
75 x 11
7 + 5 =12
Insert the second digit as before between the 7 and 5: 725
Then add the first digit from 12 which is 1 to the 7: answer 825!
Try it: it’s awesome! If you’d like to know more shortcuts about anything check out Thirty days has September at the library now.
