Gifted Issues Discussion homepage Forums General Discussion When will ESTIMATING be over!?

Ugh... DS8 has always liked math (well, not so much math class at school, but learning math concepts) and gotten pretty much straight 100's, but they've been doing estimating for the past month or so and UGH! It's been rough. DS haaaates it and keeps 'forgetting' to estimate and instead just putting down the answers. What is the point of teaching 3rd graders to estimate again? Kids who don't even have their multiplication tables memorized? Who haven't learned fractions or percentages? I mean, what are we doing with the match curriculum!?

Estimation is a good skill to have. It can enable simpler problem solving and rapid decision making, and often comes up in real life in simple mathematical situations and more complex ones as well. It's also a good way to trap errors in math work; if a calculation gives an answer that's way off the mark, a student may realize it because the answer doesn't make sense, i.e. doesn't agree with an estimation that may be unconsciously made.

When we were using Singapore Math, I liked the way it would periodically (and relatively briefly) reintroduce estimation, in terms of rounding amounts in order to give an estimated calculation result. It would then ask the student to do the precise calculation and ask if the answer made sense.

All that said, I would certainly chafe at too much estimation, especially of just the counting sort. Past a certain point it can be time-wasting to sit and estimate how many marbles are in a picture.

It will be over pretty soon. It was a struggle for both of my kids... partly because every time they did it, the teacher would have different rules for how they should do it. It seemed like my kids always had the wrong answers (per the teacher's requirements), but I could see how they got it, and it seemed like a reasonable way to estimate (eg, the way I would do it in real life). If it is any consolidation, my daughter who is a senior in high school is taking AB Calculus BC this year, and planning to major in Physics in spite of her struggles with estimating so many years ago.

I remember how much I hated estimation ... and how my adverse reaction to it came back to life when my stepson was doing estimation at school. I just never (and still can't) grasp the concept of WHY estimate when you can have the correct answer? ... I do understand all the points lucounu mentioned ... but still ...
And I am already seeing the same lack of understanding for estimating in DS4. It's either the correct result or nothing at all for him.

My math challenge in the 6th grade social studies class I teach involved estimating this time around.

Given that there are almost 70 standard miles in a degree of latitude, show *how* you can estimate the circumference of the earth.

But I guess I'm forcing them to estimate by not telling them that there are 69.1 or so standard miles in a degree of latitude. I also drew a big circle on it to encourage them to use a picture.

It's a good skill, but I think they introduce it too early. It's annoying for mathy kids who easily solve these easy problems correctly anyway. DD did a lot of them backwards.

The types of problems he's having to do are like 36x7 and 29x4.

I think he's very irritated because he really does want practice at doing ACTUAL multiplication problems, but this instead becomes an exercising in remembering the teachers guidelines on how to estimate.

I think the key thing is that they shouldn't be estimating things to which they can calculate the exact answer (reasonably in the circumstances) when they first start estimating at least. Later, when they're comfortable with estimating, that's fine, but they do need to see that estimating lets them do things they couldn't do otherwise!

Here's a question DS8 (well, he's DS9 now, but he was DS8 then) recently did [ETA with no calculator allowed, obviously]:


Here's another; this one is even better, actually.


ETA: this is one of the areas DS finds hardest; picking the right kind of approximation to get you the amount of precision you need is a bit of an art. If this is typical, and it sounds as though it is, I suppose that's why teachers resort to setting such "easy" estimation questions. But I really doubt it achieves anything.

Yes - that's a cute question, but I'm not sure it's really estimation in the sense people are talking about here. There's no need for them to do any estimation; they are using as input your approximate data, and maybe you're talking about significant figures and how they should report the answer, which is a skill related to estimation, but there's no reason they shouldn't do their sum (70 x 360) exactly, is there?

One way to motivate estimation is to calculate the cost of buying things. E.g. if one apple pie costs $1.98, how much does it cost to buy 5 apple pies?