Square any two digit number: Suppose the number is 47 Look for the nearest multiple of 10 Example: The nearest number is 50. We will reach 50 if we add 3 to 47 So multiply (47+3) x (47-3) = 50 × 44 = 2200 This is the 1st interim answer. We had added 3 to reach the nearest multiple of 10 that is 50 thus 3x 3 = 9 This is the second interim answer. The final answer is 2200 + 9 = 2209 Multiply any two numbers from 11 to 20 in Easy Way: Example: Take 15 × 13 Take the larger no on the top and the second digit of the smaller no. in the bottom. 15 3 Add 15+3 = 18 . Then multiply 18 × 10 = 180 Now multiply the second digit of both the no.s (ie; 5 × 3 = 15) Now add 180 + 15. Here is the answer 180 + 15 = 195 This is a simple trick. It will help you a lot. Multiply any two digit number with 11: Example: 27 × 11 Divide the number as 2 _ 7 Add 2 + 7 = 9 Thus the answer is 2 9 7 But there is one complication. If you take a number lik...