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Hey all you MATHY people, I have a question!


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WHY should students know how to do Front End Estimation?

 

It is in our Singapore Math curriculum and it comes after we have already taught how to round numbers. I know WHAT it is. I just can't figure out WHY they would need to know it. It seems to be just confusing them. I need a pedagogical reason for teaching it because my math teachers and my students are frustrated. I had never even heard of it until this week!

 

For those of you following along:

 

typical rounding of numbers:

 

576 + 324

600 + 300

 

In front end estimation, you take the first digit and put a zero for everything else:

 

576 + 324

500 + 300

 

 

 

Yes I know it is just another (less accurate) way of estimating but I need to know if there is some other skill they will learn later that builds on this? It just seems sort of pointless.

 

 

 

 

.

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I'm with you. I've never seen it in my version of SM or I would have skipped it. It has to be a US standards thing for testing purposes. Is it? I ran across the concept when we used to do K12 with a VC and I skipped it then. It confused me and I love to teach math. I can't imagine what it is good for.

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Doesn't make any sense to me either :confused:

I guess it could be a preliminary step toward proper estimation, to show the kids how rounding up when appropriate generates a more accurate estimate? But even then it seems a bit silly to teach them the wrong way and then ask them to unlearn it.

Edited by Hotdrink
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I am sorry if I offend anyone,

but it seems like an absolutely

pointless thing to learn.

 

I am a Chemical Engineer, have been

great at math my whole life.

Love math.

 

I would forget about the

whole thing and learn normal

arithmetic. I would forget the

silly term "front end estimation."

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I'm with you. I've never seen it in my version of SM or I would have skipped it. It has to be a US standards thing for testing purposes. Is it? I ran across the concept when we used to do K12 with a VC and I skipped it then. It confused me and I love to teach math. I can't imagine what it is good for.

 

It is in our U.S. standards and in the U.S. standards version of SM which we use. It was also in our previous Houghton Mifflin series.

 

I didn't want to automatically dismiss it just because I was unfamiliar with it but I honestly cannot find a reason for using it???

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It is in our U.S. standards and in the U.S. standards version of SM which we use. It was also in our previous Houghton Mifflin series.

 

I didn't want to automatically dismiss it just because I was unfamiliar with it but I honestly cannot find a reason for using it???

 

Dr. Math seems to agree:

 

"...it's just a school method, not something mathematicians bother with."

 

http://mathforum.org/library/drmath/view/59027.html

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I think parents who aren't strong in math (such as me) tend to be overly respectful of textbooks and so on. We should probably feel free to omit things that seem pointless, especially after verifying the pointlessness with People Who Get Math.

 

My son's curriculum devotes a couple of lessons to something called a Problem Solving Chart, which basically entails rewriting a simple word problem into a complicated and repetitive table before you're allowed to solve it. I tried my kid on a few problems without the chart, he had no difficulty, so we skipped those lessons. Similarly, in the basic operations, our curriculum presented two 'different' ways to subtract. When I looked at them, they were actually both doing the same thing, just writing the workings differently, so does it matter if you only learn one, as long as you can do the subtraction and understand what you're doing? I don't think so.

 

Probably because most curricula are either designed for schools or modified from something designed for schools, they put in everything that might conceivably be helpful to a few students, and make every student learn it. Whereas with only a few students, the home educator can relatively easily figure out what bits her student isn't going to need.

Edited by Hotdrink
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I am mathy, and did SM all along with all 3 kids, and I see no point. It is just a quick, dirty way of achieving what rounding and then estimating achieves, but is not as accurate as rounding first.

 

I don't think there are any skills that build on this.

 

It is crazy easy, though, so I can't see any reason to skip it, either. You should be able to teach and master it in under 5 minutes. :)

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It is in our U.S. standards and in the U.S. standards version of SM which we use. It was also in our previous Houghton Mifflin series.

 

However, it is not in the US Edition (pre-standards) which is more closely based on the Singapore books. This is obviously some screwy American idea that got added when the US "standards" did. So I'd skip it.

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Dr. Math seems to agree:

 

"...it's just a school method, not something mathematicians bother with."

 

http://mathforum.org/library/drmath/view/59027.html

 

:iagree:

 

Thats what started to bother me about khan academy practice problems - they started padding it with the useless practice problems that schools use to fill out the year. it does not contribute to a solid understanding of numbers, does not really prepare you for later math.

 

the one that was bothering me with khan academy was lower level probability - they basically give one kind of probability problem and teach you the steps to solve it, at a stage where you cant really understand the concepts. they arent teaching the concepts you wouldnt be able to use it for any other problem. they only have it there so they can check off that they covered probability on their standards.

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I think lots of math programs teach estimation. In my opinion (having taught K-11th grade so far), it helps with two things. One, it helps with mental math when they need to work problems quickly on tests. Two, it helps because you need to be able to estimate when working division problems.

 

eta: I haven't used any of the programs in question, so I cannot speak to the progression issue. I'm also not mathy, so maybe that's why it makes more sense to me, lol.

Edited by Mrs Mungo
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I am mathy (have a math degree) and my oldest went through Singapore 6B and much of NEM 1 (using AoPS now). Meh - I think it's good to have some estimation skills, especially for dividing. But this particular method? No. We really just brushed over it.

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I just asked DH (who uses a lot of math in his work) if he could think of anything that might make this a useful skill, and he couldn't either. We did decide that sometimes you might want to do that in reverse (round everything up) if you're trying to keep your groceries under a certain budget amount or something like that.

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