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Showing posts from September, 2011

10 Easy Arithmetic Tricks

Math can be terrifying for many people. This list will hopefully improve your general knowledge of mathematical tricks and your speed when you need to do math in your head. 1. The 11 Times Trick We all know the trick when multiplying by ten – add 0 to the end of the number, but did you know there is an equally easy trick for multiplying a two digit number by 11? This is it: Take the original number and imagine a space between the two digits (in this example we will use 52: 5_2 Now add the two numbers together and put them in the middle: 5_(5+2)_2 That is it – you have the answer: 572. If the numbers in the middle add up to a 2 digit number, just insert the second number and add 1 to the first: 9_(9+9)_9 (9+1)_8_9 10_8_9 1089 – It works every time.   2. Quick Square If you need to square a 2 digit number ending in 5, you can do so very easily with this trick. Mulitply the first digit by itself + 1, and put 25 on the end. That is all! 25 2...