MAXZONE ACADEMY

  This post is made to learn “How to multiply, in your head, any two-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 the 3 and the 2, and there is your answer: 3 5 2 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!   Now before you get too excited, I have shown you only half of what you need to know. Suppose the problem is 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 Think of the problem this way: 1 835 935   Here is another example. Try 57 x 11. Since 5 + 7 = 12, the answer is: 1 527 627   Okay, now it’s your turn. As fast as you can, ...

As you probably know, the square of a number is a number multiplied by itself. For example, the square of 9 is 9 x 9 = 81. This post is made to enable you to easily calculate the square of any two-digit or three-digit (or higher) number.  That method is especially simple when the number ends in 5, so let’s do that trick now. To square a two-digit number that ends in 5, you need to remember only two things. 1. The answer begins by multiplying the first digit by the next higher digit. 2. The answer ends in 25. For example, to square the number 35, we simply multiply the first digit (3) by the next higher digit (4), then attach 25. Since 3 x 4 = 12, the answer is 1225. Therefore, 35x35 = 1225.  Our steps can be illustrated this way: How about the square of 85?  Since 8 x 9 = 72,  we immediately get 85 x 85 = 7225. Similarly we can calculate the following squares  15 x 15 = 225  25 x 25 = 625  35 x 35 = 1225  45 x 45 = 2025  55 x 55 = 3025 ...