Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫  π  -¹ ² ³ °

You are not logged in.

## #1 Help Me ! » price matching... » 2011-10-07 09:29:20

learn_everything
Replies: 1

Hello all,

Ok, here is the scenario.  I don't have a Costco card but I need to purchase toilet tissue in bulk.  The cheapest tissue in bulk at Costco here is \$27.99 for 48 rolls of tissue.  So, each roll of tissue is about .58 cents.  The store that I shop at told me that they price match with any store here including Costco.  But, of course, this store doesn't sell tissue in bulk.  Nevertheless, they told me that they will give me the same amount of toilet tissue at the same rate that Costco does.  So, in essence, they will price match with Costco regarding toilet tissue.  I just have to figure how much toilet tissue at their store would be equivalent to bulk purchasing the toilet tissue I mentioned above from Costco.

So, my question for you all is what do I do at the store that I'm shopping at right now?  Do I just go there and grab 48 rolls of tissue and tell them that Costco sells their bulk tissue for \$27.99 for 48 rolls and that they have to price match that policy?  I just want to make sure before I go there.  Thank you!

## #2 Re: Help Me ! » Real life applications for every math concept » 2011-01-11 20:56:44

I am still here bobbym.  I have decided to just learn whatever mathematics I need when/if the situation calls for it in my upcoming job endeavors.  So, I will post any job-related math problems I have here in the future if that is ok with you.  Thank you!

## #3 Re: Help Me ! » Real life applications for every math concept » 2011-01-07 21:08:40

Oh no, I was agreeing with you regarding the zoo example.  It's just the fact that she seemingly used the wrong formula confused me and sort of invalidated the rest of what she did in the problem. (at least in my mind)

I didn't read the second link you posted because I perceived the first link to be incorrect.  However I just read the second link you posted and I have to say, I think I get it now!!  Thank you very much!  (the building example w/ the bushes did it for me!)

But, in retrospect, square roots don't seem to be able to stand on their own in terms of being essential.  It was only via the Pythagorean theorem that I was able to see how important square roots/Pythagorean theorem combination are.  Anyhow, I guess that's irrelevant now though.  I am glad to finally understand this though.  I am excited to learn more!

P.S. - I think we should analyze that zoo example later though.  I'm still blurry on that one.

## #4 Re: Help Me ! » Real life applications for every math concept » 2011-01-07 20:25:26

** Please keep in mind that I am not asking about "why do I need to learn math" in a general sense because simply stating that math is needed if you intend to study __ or __ doesn't help anyone.  I am specifically asking for real world problems that I can attempt to solve on my own but ultimately I am able to eventually come to the conclusion that knowledge of the particular math concept is absolutely necessary to complete the real world task I intend to work on. **

I think your explanations are focusing almost exclusively on "why is math important" in a general sense while, as I stated, I am specifically looking for a real life practical situation that I can see myself in (not impractical situations) in which I must use square roots or I will not be able to solve whatever it is I'm working on.

However, I did like the zoo example you posted but what about:
http://www.ehow.com/how_5185561_calculate-area-isosceles-triangle.html

The formula she used is for a triangle, I thought an isosceles triangle had a different formula...

But anyway, I think that I should just deal with math when I am "forced to" in a practical sense.  If I need it when I am building something in my daily life then it will be explicit and I won't have to wonder.  The reason why I'll need will be right in front of me.  Thank you nevertheless!

## #5 Re: Help Me ! » Real life applications for every math concept » 2011-01-07 17:09:28

I think you are missing my point.  I am not able to accept something as vital if I am not able to see the vitalness of it.  I can not state that math is important "just because it is".  There are some areas of math that I know are essential and are used everyday.  I did not inquire about them, I am inquiring about square roots since I don't see what makes them essential to learn.  If you were to tell me that one doesn't really need to know square roots and that learning it is optional then I would be at ease, I would notate that in my notes, and I would happily move along and search for other concepts that don't make sense to me.  But since you feel they are absolutely necessary to know then I really would like to know why.

In my opinion, IF square roots are absolutely essential, what I am asking should not be that difficult to answer.  I can't attempt to persuade a student or myself that this concept is important with what we've discussed so far.

Honestly, I think we are on the same page really.  The example about the nails that you listed shows this.  I stated that square roots are not necessary and so did you.  They can help you and sometimes they can help you do what your doing a bit faster but they are not essential.  And that is what I wanted to ascertain.  Namely, is learning this concept of square roots essential or optional.  I think optional.  Is that correct?

## #6 Re: Help Me ! » Real life applications for every math concept » 2011-01-07 14:39:37

Bobbym, regarding square roots, my thought pattern was correct then, because you do, in fact, want equal pressure exerted on the ladder, so it doesn't dig into the "soft ground/mud".  By the way, the examples you give me, PLEASE make them as real as possible.  If not then I will not be able to understand it.

So, is my thinking above correct about square roots?  In summary, one uses square roots to determine the longest side of a triangle when one is building a structure or something else where the builder has two of the sides but not the longest side.  Square roots are not obligatory to learn since one actually could just measure the longest side with measuring equipment.

Now, I wrote the first paragraph above but I don't know that I really believe it.  Why?  Because even if what I wrote above is correct I still don't see how a carpenter would use that information or would not be able to build a structure without that knowledge.  When I was at work today, I specifically looked for things, structures, etc. around my workplace that a carpenter would have not been able to build without the knowledge of square roots.  I didn't see a single thing.  Perhaps you can list a 100% real life example where knowledge of square roots is an absolute must because I still don't get it.  I am trying though.

## #7 Re: Help Me ! » Real life applications for every math concept » 2011-01-06 10:47:54

I still don't get it, bobby.  I presume that what is going on in your mind with this is:

You have just found your cat in a tree.  You don't have a ladder so you borrow your neighbor's.  It is 21 feet long.  You can measure the pole that the cat is in by standing the ladder up to the pole and marking where you think the pole stops and measuring that with a measuring instrument.  So, you have two lengths.  Ladder - 21 feet and pole - 13 feet.  I don't know where you got 17 feet from and also I don't know what the ground being "too soft" means but I think what you are trying to do is set the ladder up in a way that if any pressure/weight is applied to it (the cat descending it), the weight will be evenly distributed.  This is why you want to set the ladder up in a right triangle with the pole and the ground.

But I'm not sure what to do now though.  I still don't understand why square roots are obligatory here.  In a situation such as the example you listed, I would just position the ladder to where the cat could reach it and hold the ladder with assistance from others.  Of course, I would attach a plank or something to the ladder first though because a cat can not just descend a ladder.

On a more general note though, perhaps one should learn math as they need it instead of learning it beforehand.  If so, then my current approach is totally incorrect...

## #8 Re: Help Me ! » Real life applications for every math concept » 2011-01-06 08:44:30

Thank you, bobbym!

Well, so far, I am on the year one curriculum but while I am re-learning super basic concepts, I click on the other links on the page and I end up at more advanced concepts.  So, if I am jumping around a bit and you feel that is hampering my understanding/progress then please just let me know and I will stick with curriculum until the concept that Im encountering makes sense.

So, I wonder what real world problem(s) absolutely requires the knowledge of:
#1.  square roots

I have done some searching myself also and I have found this:
http://www.homeschoolmath.net/teaching/why_need_square_roots.php

This seems to be a good page for what Im asking about in general but I still didnt exactly understand the example that the author of that article mentioned regarding constructing a building.  But I absolutely love the way he progressed with his example.  Presenting a real world problem to students.  Next, asking the students to solve the problem the best way that they know how.  Finally, after the students are not able to solve the problem on their own (using the simple arithmetic that almost everyone can appreciate/accept), the teachers steps in and introduces to them the mathematical concept(s) that they are to learn at that time and shows them that they can only solve the specific real world problem with the math concept that he is teaching them.

This way the knowledge sticks and students can see how they can use it.  I strongly feel that this would also encourage students to come up with other ways to solve the specific real world problem.  This kind of student activity gets students involved with math and only makes the field of mathematics much better.

But anyway, the square root question above is my current question.  Thank you!

## #9 Help Me ! » Real life applications for every math concept » 2011-01-05 23:06:09

learn_everything
Replies: 19

I am 24 yrs old and I am going through the entire curriculum on the mathisfun.org site as well as the p12.nysed.gov curriculum linked on the curriculum page.  For now, I just want to ask why is there no real life practical application listed of each and every single concept listed on the curriculum progression pages?

I graduated high school but I was not good at math.  That fact really didn't bother me because I saw no need for mathematics.  I work as a translator so I did not see daily or at any time really any real life, real world problems that absolutely necessitated a ton of math that I was supposed to learn in school.  Now, I am starting to study other fields that supposedly requires me to be very comfortable with very advanced mathematics.  That is why I'm going through your entire curriculum (along with Khan Academy's curriculum) to solidify my knowledge of mathematics from the absolute basics to very advanced math.

BUT

I have to know very very precisely why I need to know each concept that is listed in the curriculums here and elsewhere.  Not to belabor the point, what specific real world problem(s) specifically requires that the individual know the concepts listed on the curriculums.  Now, of course, we all know that there are a lot of topics/concepts in the curriculum here, so what I wanted to do is perhaps have this thread as a place where I can list a concept and then someone can list the real world problem that can only be solved by proficiency of the aforementioned concept(s).

** Please keep in mind that I am not asking about "why do I need to learn math" in a general sense because simply stating that math is needed if you intend to study __ or __ doesn't help anyone.  I am specifically asking for real world problems that I can attempt to solve on my own but ultimately I am able to eventually come to the conclusion that knowledge of the particular math concept is absolutely necessary to complete the real world task I intend to work on. **