Mental MathDate: 07/25/2003 at 13:35:27 From: Charlie Subject: Mental Math I would like to find a trick for multiplying by 3367. 3367*27 3367*33 3367*32 3367*18 3367*17 3367*14 3367*15 Date: 07/31/2003 at 09:42:23 From: Doctor Stephanie Subject: Re: Mental Math Hi Charlie, When I have seen these problems on tests that are specially designed for mental math, I have tried to find similarities or trends from other problems like them. You really are on the right track. When I have seen a problem that has multiplied 3367 by another number, I have noticed that almost always the other number is a multiple of 3. When you multply 3367 by three you then find a number that is very common in the "mental math world," 10101. An example of how to use this would be to not view 3367 as 3367, but as 10101 * (1/3). Here is an example of how you might be able to use this to your advantage: 3367 X 15 = 10101 X (1/3) X 15 = 10101 X 5 = 50505 Keep in mind that this trick is only useful if the other number is divisible by 3. I hope this perspective has helped you find another way to approach the problem or even find an even better "trick". If you have any more questions or if this is unclear, feel free to write back! - Doctor Stephanie, The Math Forum http://mathforum.org/dr.math/ |
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