Front End Estimation of Addition ProblemsDate: 09/06/2005 at 19:53:51 From: Kristin Subject: front end estimation Could you give me an example problem so I can learn how to do front end estimation? Here's an example: 436 400 + 517 + 500 _____________ 900 Is this correct? Date: 09/06/2005 at 22:59:14 From: Doctor Peterson Subject: Re: front end estimation Hi, Kristin. Yes, that's correct. The main idea of FEE is that the "front-end" digits (the ones on the left) are the most important because their place value is the greatest. So if you want to estimate by ignoring most digits and using as few as possible, you will do best if you use only the "front end", and replace everything else by zero, as you did. There are other tricks for getting a better estimate which you will be learning later--these may be called "adjustments", or may be taught as "rounding". What you've learned should be enough for the moment, but you will do well by thinking after doing each problem, "How far off do I expect my answer to be? Will the exact answer be more or less than what I estimated?" Then do the exact addition and see if you were right. Do that enough, and you'll be a good estimator! So make up your own problems, and then check your answers that way. That will be worth more than any sample problems I could give you. You may run across some tricky cases; if you don't understand why some of your estimates are farther off than you expected, write back and tell me what you found, and we can discuss it. - Doctor Peterson, The Math Forum http://mathforum.org/dr.math/ |
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