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Everyday Math was being used in our school district. My son brought home a multiplication worksheet on estimating. He had 'estimated' that 9×9=81, and the teacher marked it wrong. I met with her and defended my child's answer. The teacher opened her book and read to me that the purpose of the exercise was not to get the right answer, but was to teach the kids to estimate. The correct answer was 100: kids were to round each 9 up to a 10. (The teacher did not seem to know that 81 was the product, as her answer book did not state the same.)
I have to defend the teaching of estimation. It's a useful tool to quickly check the reasonableness of calculated answers. Marking 9x9=81 as wrong for an estimate is the correct thing to do. (It is, though, a poor example to use for teaching estimation. The kid should have already been taught that by memorizing the 'times table'.)
25 posted on 01/13/2008 7:22:35 PM PST by Bob
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To: Bob

What cr@p. The goal of estimation, as used in business and engineering, is to estimate as closely as possible to the correct answer with the least effort. If the actual correct answer is available with the least effort, THAT IS THE BEST ESTIMATE. The teacher in this case simply does not understand the concept. Estimation is about using the simplest process to arrive at the estimate. Multiplying 9 x 9 is the simplest process and therefore the best estimate. Scaling 9 to 10 and multiplying 10 x 10 takes more steps and is therefore a poor estimate.

In other words, the teacher is not intelligent enough to understand what he/she is supposed to be teaching. Unfortunately, understanding the subject matter is no longer the most important requirement in the primary education profession. Towing the leftist/NEA line is far more important.


38 posted on 01/13/2008 7:45:26 PM PST by piytar
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To: Bob

“I have to defend the teaching of estimation. It’s a useful tool to quickly check the reasonableness of calculated answers. Marking 9x9=81 as wrong for an estimate is the correct thing to do. (It is, though, a poor example to use for teaching estimation. The kid should have already been taught that by memorizing the ‘times table’.)”

Wow, this is a new definition. The estimate is in the calculation? I constantly used estimates in business over many years, but the estimates were estimated results CALCULATED EXACTLY. Never heard of estimated calculations.

And I’m confident the estimated calculations are total nonsense, of little or no value in the real world of business, science, or any other field.

Sounds like just another made up method to give a passing grade to students who can’t pass when exact answers must, be, er, exact, as in real world math applications.

But any time time you want me to make change for you, I’ll be happy to do it using estimations.


77 posted on 01/13/2008 8:49:28 PM PST by Will88
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To: Bob; piytar

I have often had to use estimates, until I had time and/or tools to do an accurate answer.

To me 80 or 90 would be correct, 9 up to 10 x 9 = 90- 10% =80

I have used this method many times.


100 posted on 01/13/2008 9:14:45 PM PST by razorback-bert (Remember that amateurs built the Ark while professionals built the Titanic.)
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