Instant Multiplication (Part 1)

Let’s begin with how to multiply, in any two-digit number by eleven. Consider the problem:

36 x 11

To solved this, simply add the digits 3 + 6 = 9, put the 9 between the 3 and the 6, and there is your answer:

396

Now try another:

52 x 11

Since 5 + 2 = 7, your answer is simply

572

Now I show you another problem solution:

85 x 11

Although 8 + 5  = 13, the answer is NOT 8135.

As before, the 3 goes in between the numbers, but the 1 needs to be added to the 8 to get the correct answer:

935

Here is another example. Try 57 x 11.

Since 5 + 7 = 12, the answer is 627.

Now we move forward multiplying three-digit numbers.

314 x 11, the answer still begins with 3 and ends with 4. Since 3 + 1 = 4, and 1 + 4 = 5, the answer is 3454.

Figure it out yourself!