Why do they find basic maths so unachievable??

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  • EnidanEnidan Posts: 13,101
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    Otto J wrote: »
    Or for people to congratulate themselves on possessing a scientific calculator (as if handing over £20 in WH Smith required a gigantic intellect).

    Besides, it's quite misplaced to apply BODMAS to such a trivial calculation, which will always be context-dependent.

    For instance, if the 5 innumerate members of a marketing department are giving 2 DVDs and 3 gift books to each of 11 attendees at a seminar, and want to know how many items they'll each have to wrap, it won't be much help if they punch 2 + 3 * 11 / 5 into BODMAS-savvy Google and come up with 8.6.

    The innumerate's sum was poorly presented as they forgot to use brackets. :rolleyes:

    11(2+3) = 11
    5
  • [Deleted User][Deleted User] Posts: 934
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    Those innumerate members of said marketing department should be placed in a secure, soft, padded environment where they can't do anyone any harm.

    They're not bad at marketing. But I saw one once use a calculator to work out 36 divided by 3.
  • [Deleted User][Deleted User] Posts: 934
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    Enidan wrote: »
    The innumerate's sum was poorly presented as they forgot to use brackets. :rolleyes:

    That was my conclusion too. Though they are almost as unlikely to think of using brackets as to know that Google applies BODMAS.
  • Bachelor FrogBachelor Frog Posts: 69
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    floopy123 wrote: »
    Just to add one last thing... none of you clever maths people have explained how a number multiplied by zero equals zero.

    If I had four bags of crisps on a table and multiplied them by zero crisps, wouldn't the four packets still remain on the table. I thought zero crisps meant no crisps on the table! 4 x NOTHING must equal 4.

    But according to the rules of maths the four crisp packets would magically disappear!

    It is any wonder people struggle with maths when it's full of gobbledygook

    By the way, would anyone want one of my crisps? They're cheese 'n' onion. :D

    8/10 for your troll up to this point, but then you exposed yourself by driving forward with this point that nobody was biting. Good effort.
  • Steve9214Steve9214 Posts: 8,402
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    Missing the point - profit figures were completely WRONG

    Jane should know coming from a food background.
    You do not calculate profit in the way her team had.

    You always quote margin as a % of selling price - the retailers quoted that 40% margin being a good figure for a product.
    Retailers generally look for up to 40% margin of selling price.

    The Female team were quoting margin as being "factorial" - the selling price as a % of the wholesale price - giving distorted margins that the retailers could not understand.
    You cannot have a profit margin of 200% + as your selling price is set at the 100% base point.

    Maybe in other industries this factorial thing is a norm, but not when dealing with retailers, so if Jane knew this (and had spotted it) she was clearly hanging the team that did the calculations out to dry for the boardroom later.
  • EnidanEnidan Posts: 13,101
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    Steve9214 wrote: »
    Missing the point - profit figures were completely WRONG

    Jane should know coming from a food background.
    You do not calculate profit in the way her team had.

    You always quote margin as a % of selling price - the retailers quoted that 40% margin being a good figure for a product.
    Retailers generally look for up to 40% margin of selling price.

    The Female team were quoting margin as being "factorial" - the selling price as a % of the wholesale price - giving distorted margins that the retailers could not understand.
    You cannot have a profit margin of 200% + as your selling price is set at the 100% base point.

    Maybe in other industries this factorial thing is a norm, but not when dealing with retailers, so if Jane knew this (and had spotted it) she was clearly hanging the team that did the calculations out to dry for the boardroom later.

    Yes it was quite obvious that the percentages baffled them, including Jane. She has since admitted quite happily that she has no grasp of basic maths so I don't think it is in her capability to spot a mathematical error let alone use that tactically to her advantage. I am sure her bosses/business partners are cringing with embarrassment.
  • Evil GeniusEvil Genius Posts: 8,726
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    frally wrote: »

    Maths is never fun...
  • tabithakittentabithakitten Posts: 13,853
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    Maths is never fun...

    It is if you're good at it ;). It's just like anything else. Even art and p.e. (especially p.e.) can be a right royal pain in the rear end if you're cr@p at it.

    Unfortunately for the "apprentices", being sh1t at p.e. or art is a less obvious disadvantage than being rubbish at basic arithmetic (I can't even bring myself to call it maths).
  • EnidanEnidan Posts: 13,101
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    Maths is never fun...

    Sometimes I make charming little equations from the prices on my supermarket receipts, I find that fun and also useful when on a tight budget.
    I also always shop by £/kg as it make the whole supermarket experience more enjoyable and also a big eye opener in how one can be ripped of by boggofs and the like. Fun and useful.
  • njpnjp Posts: 27,583
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    Enidan wrote: »
    Sometimes I make charming little equations from the prices on my supermarket receipts, I find that fun and also useful when on a tight budget.
    I also always shop by £/kg as it make the whole supermarket experience more enjoyable and also a big eye opener in how one can be ripped of by boggofs and the like. Fun and useful.
    Tesco's own brand baked beans are a case in point. There are two varieties of multi-pack - the 4 tin and 6 tin. Which one represents better value varies from time to time, so you always have to check. Now in theory you can do this by comparing the "price per 100g" figure they give you, though those are not always to be trusted. Bogof deals complicate matters, as do coupons.

    Only the other day, for example, I had a coupon offering 55p off a 6-pack of Tesco own-brand beans. A no-brainer, you might think - especially as the 6-pack was the best value offer the last time I bought beans.

    But then I noticed that the 4-packs were £1, while the 6-pack was £2.20. So clearly Tesco management had pulled one of their periodic value-reversal tricks: 8 tins of beans could now be had for £2. But what about the coupon? Surely a 55p coupon must be worth having, and would again make the 6-pack the better deal?

    A quick calculation was needed to confirm that no, even with the coupon the 6-pack was still worse value. But I suspect a lot of people will have fallen for the trick.
  • EnidanEnidan Posts: 13,101
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    njp wrote: »
    Tesco's own brand baked beans are a case in point. There are two varieties of multi-pack - the 4 tin and 6 tin. Which one represents better value varies from time to time, so you always have to check. Now in theory you can do this by comparing the "price per 100g" figure they give you, though those are not always to be trusted. Bogof deals complicate matters, as do coupons.

    Only the other day, for example, I had a coupon offering 55p off a 6-pack of Tesco own-brand beans. A no-brainer, you might think - especially as the 6-pack was the best value offer the last time I bought beans.

    But then I noticed that the 4-packs were £1, while the 6-pack was £2.20. So clearly Tesco management had pulled one of their periodic value-reversal tricks: 8 tins of beans could now be had for £2. But what about the coupon? Surely a 55p coupon must be worth having, and would again make the 6-pack the better deal?

    A quick calculation was needed to confirm that no, even with the coupon the 6-pack was still worse value. But I suspect a lot of people will have fallen for the trick.

    Yes, an excellent example of how supermarkets take advantage of the current fashion of being proud to be innumerate. The vouchers often don't pay and it's always best to try and use offers in conjunction with each other, this can be tricky though especially when taking expiry dates into consideration.

    Once with careful calculations using dates x vouchers x offers x clubcard points I managed to do a weekly shop including 6 bottles of wine and a large chicken for under £21. I was ecstatic, every thing was working in my favour that day, I will never forget it.
  • SmintSmint Posts: 4,691
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    njp wrote: »
    A quick calculation was needed to confirm that no, even with the coupon the 6-pack was still worse value. But I suspect a lot of people will have fallen for the trick.

    I had a similar dilemma with buying KitKats for my husband's lunch - further complicated by the fact that the 2-finger bars are in a different aisle from the 4-finger ones :confused:

    I can't remember the exact prices, but the 2-finger ones were on one offer, and the 4-finger ones on a different offer, but a quick calculation to work out price per finger got me the better deal
  • [Deleted User][Deleted User] Posts: 2
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    Hey you gave nice solutions. I agree maths is tricky sometimes difficult. I am getting confused in understanding why 7 × 11 × 13 + 13 and 7 × 6 × 5 × 4 × 3 × 2 × 1 + 5 are composite numbers
    7 * 11 * 13 + 13 * 1
    13 ( 7 * 11 + 1) = 13 * 78
    7 × 11 × 13 + 13 is a composite number

    Here my query is how does 7 * 11 * 13 + 13 * 1 leads to 13 ( 7 * 11 + 1) = 13 * 78

    I was going through my chapter http://www.youtube.com/watch?v=ToNuEa2wQOk and got this query. please tell me

    7 * 11 * 13 + 13 * 1 leads to 13 ( 7 * 11 + 1) = 13 * 78
  • TogglerToggler Posts: 4,592
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    Enidan wrote: »
    Yes, an excellent example of how supermarkets take advantage of the current fashion of being proud to be innumerate. The vouchers often don't pay and it's always best to try and use offers in conjunction with each other, this can be tricky though especially when taking expiry dates into consideration.

    Once with careful calculations using dates x vouchers x offers x clubcard points I managed to do a weekly shop including 6 bottles of wine and a large chicken for under £21. I was ecstatic, every thing was working in my favour that day, I will never forget it.

    I take my hat off to you - £21 must be a record! I check every price in supermarkets, but note that sometimes the price per kilo is not displayed for comparison reasons - eg for a 300g and a 500g box of cereal today in Sainsbugs, so further calculations had to be made for establish best value. And it was the 500g! I always remember checking out packs of paracetamol (in the days when you could buy more than 1 pack of 10) and buying the big pack was dearer than buying two small packs. Economies of scale - wossat?
  • [Deleted User][Deleted User] Posts: 210
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    kpinky wrote: »
    Hey you gave nice solutions. I agree maths is tricky sometimes difficult. I am getting confused in understanding why 7 × 11 × 13 + 13 and 7 × 6 × 5 × 4 × 3 × 2 × 1 + 5 are composite numbers
    7 * 11 * 13 + 13 * 1
    13 ( 7 * 11 + 1) = 13 * 78
    7 × 11 × 13 + 13 is a composite number

    Here my query is how does 7 * 11 * 13 + 13 * 1 leads to 13 ( 7 * 11 + 1) = 13 * 78

    I was going through my chapter http://www.youtube.com/watch?v=ToNuEa2wQOk and got this query. please tell me

    7 * 11 * 13 + 13 * 1 leads to 13 ( 7 * 11 + 1) = 13 * 78

    I have absolutely no idea what you mean by "composite numbers" but as to your question

    why does

    7 * 11 * 13 + 13 * 1 = 13 ( 7 * 11 + 1)

    Well this is the same as asking why
    xy * x = x ( y +1)

    Well all you need to do is to evaluate what is in the brackets, remember all brackets mean is to multiply, and to do that one multiples what is outside the brackets to ALL the elements inside a bracket, and if an element in the bracket is a product or division e.g. 7*11 one can treat that as one element.

    so just as

    x ( y +1 ) = x (y) + x (1) = xy +1

    So
    13 ( 7 * 11 + 1) = 13 ( 7 * 11) + 13 (1) = 13 * 7 * 11 + 13

    if one wants to do the reverse, i.e. start with

    13 * 7 * 11 + 13 and convert it into the bracketed form above

    one first recognises that 13 is common to the two elements of the sum, and so doing it very long handed

    13 * 7 * 11 + 13
    multiply the expression by 13/13, which is 1 and therefore does not affect the value of the expression
    = (13 * 7 * 11 + 13) * 13 / 13
    move the divide 13 inside the brackets
    = ( (13 *7 *11) / 13 + 13 /13) *13
    evaluate the 13/13 elements, which are =1, in the brackets
    = ( ( 1 * 7 * 11 ) + 1 ) * 13
    = ( 7 * 11 + 1 ) * 13
    = 13 ( 7 * 11 +1 )
  • njpnjp Posts: 27,583
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    -Flossie- wrote: »
    I have absolutely no idea what you mean by "composite numbers"
    Non-primes, basically. Not a term I had come across before either...
  • EnidanEnidan Posts: 13,101
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    -Flossie- wrote: »
    I have absolutely no idea what you mean by "composite numbers" but as to your question

    why does

    7 * 11 * 13 + 13 * 1 = 13 ( 7 * 11 + 1)

    Well this is the same as asking why
    xy * x = x ( y +1)

    Well all you need to do is to evaluate what is in the brackets, remember all brackets mean is to multiply, and to do that one multiples what is outside the brackets to ALL the elements inside a bracket, and if an element in the bracket is a product or division e.g. 7*11 one can treat that as one element.

    so just as

    x ( y +1 ) = x (y) + x (1) = xy +1

    So
    13 ( 7 * 11 + 1) = 13 ( 7 * 11) + 13 (1) = 13 * 7 * 11 + 13

    if one wants to do the reverse, i.e. start with

    13 * 7 * 11 + 13 and convert it into the bracketed form above

    one first recognises that 13 is common to the two elements of the sum, and so doing it very long handed

    13 * 7 * 11 + 13
    multiply the expression by 13/13, which is 1 and therefore does not affect the value of the expression
    = (13 * 7 * 11 + 13) * 13 / 13
    move the divide 13 inside the brackets
    = ( (13 *7 *11) / 13 + 13 /13) *13
    evaluate the 13/13 elements, which are =1, in the brackets
    = ( ( 1 * 7 * 11 ) + 1 ) * 13
    = ( 7 * 11 + 1 ) * 13
    = 13 ( 7 * 11 +1 )

    Well explained, with the final answer being the composite number 1014. :)
  • njpnjp Posts: 27,583
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    njp wrote: »
    Tesco's own brand baked beans are a case in point. There are two varieties of multi-pack - the 4 tin and 6 tin. Which one represents better value varies from time to time, so you always have to check. Now in theory you can do this by comparing the "price per 100g" figure they give you, though those are not always to be trusted. Bogof deals complicate matters, as do coupons.

    Only the other day, for example, I had a coupon offering 55p off a 6-pack of Tesco own-brand beans. A no-brainer, you might think - especially as the 6-pack was the best value offer the last time I bought beans.

    But then I noticed that the 4-packs were £1, while the 6-pack was £2.20. So clearly Tesco management had pulled one of their periodic value-reversal tricks: 8 tins of beans could now be had for £2. But what about the coupon? Surely a 55p coupon must be worth having, and would again make the 6-pack the better deal?

    A quick calculation was needed to confirm that no, even with the coupon the 6-pack was still worse value. But I suspect a lot of people will have fallen for the trick.
    Time for an update. Another week, another set of Tesco value-reversals. This week, a 4-pack of beans are £1.68, whereas a 6-pack are £2.00. So now the 6-pack is better value. And finally the 55p coupon was worth using, because it made the 6-pack slightly better value than last week's 4 packs. But only just.
  • EnidanEnidan Posts: 13,101
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    Toggler wrote: »
    I take my hat off to you - £21 must be a record! I check every price in supermarkets, but note that sometimes the price per kilo is not displayed for comparison reasons - eg for a 300g and a 500g box of cereal today in Sainsbugs, so further calculations had to be made for establish best value. And it was the 500g! I always remember checking out packs of paracetamol (in the days when you could buy more than 1 pack of 10) and buying the big pack was dearer than buying two small packs. Economies of scale - wossat?

    I have noticed this too, on some products Tesco don't even put the weight on the packet. Tesco had a special offer for a pack of (unweighted) vine tomatoes for £1.00 .Initially that looked like a good deal but after finally locating some scales I weighed the pack and then compared that to the loose vine tomatoes and to my surprise the same amount of loose vine tomatoes cost 35p. I am thinking about shopping elsewhere, they treat their customers with contempt.
    njp wrote: »
    Time for an update. Another week, another set of Tesco value-reversals. This week, a 4-pack of beans are £1.68, whereas a 6-pack are £2.00. So now the 6-pack is better value. And finally the 55p coupon was worth using, because it made the 6-pack slightly better value than last week's 4 packs. But only just.

    Thanks for the update, a good example of successful coupon/offer combining.
  • [Deleted User][Deleted User] Posts: 2
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    -Flossie- wrote: »
    I have absolutely no idea what you mean by "composite numbers" but as to your question

    why does

    7 * 11 * 13 + 13 * 1 = 13 ( 7 * 11 + 1)

    Well this is the same as asking why
    xy * x = x ( y +1)

    Well all you need to do is to evaluate what is in the brackets, remember all brackets mean is to multiply, and to do that one multiples what is outside the brackets to ALL the elements inside a bracket, and if an element in the bracket is a product or division e.g. 7*11 one can treat that as one element.

    so just as

    x ( y +1 ) = x (y) + x (1) = xy +1

    So
    13 ( 7 * 11 + 1) = 13 ( 7 * 11) + 13 (1) = 13 * 7 * 11 + 13

    if one wants to do the reverse, i.e. start with

    13 * 7 * 11 + 13 and convert it into the bracketed form above

    one first recognises that 13 is common to the two elements of the sum, and so doing it very long handed

    13 * 7 * 11 + 13
    multiply the expression by 13/13, which is 1 and therefore does not affect the value of the expression
    = (13 * 7 * 11 + 13) * 13 / 13
    move the divide 13 inside the brackets
    = ( (13 *7 *11) / 13 + 13 /13) *13
    evaluate the 13/13 elements, which are =1, in the brackets
    = ( ( 1 * 7 * 11 ) + 1 ) * 13
    = ( 7 * 11 + 1 ) * 13
    = 13 ( 7 * 11 +1 )

    Hey -Flossie- thank you for giving me clarification. Now i understood how to solve. Hey can you please clarify me one thing what are the examples of Pythagorean triplets http://youtu.be/2BUnS3E7j-U i have one example (3,4,5) can you help in list 10 more examples of Pythagorean triplets
  • EnidanEnidan Posts: 13,101
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    kpinky wrote: »
    Hey -Flossie- thank you for giving me clarification. Now i understood how to solve. Hey can you please clarify me one thing what are the examples of Pythagorean triplets http://youtu.be/2BUnS3E7j-U i have one example (3,4,5) can you help in list 10 more examples of Pythagorean triplets

    I hope you are not getting Flossie to do your maths homework. :mad:
  • rob1973rob1973 Posts: 4,236
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    idiot_box wrote: »
    Charming:cry:

    There do not need to be any brackets in the formula, you just identify the functions that are in the formula and do them in the BODMAS order.

    I learned this at the age of 11.

    I have an A in Maths at O-level
    I have A Level Maths
    I am an accountant

    ;)

    So you can't be trusted with figures then! :D

    I'm sorry but I'm with Floops, and don't give me this 'I'm an accountant' flim flam. Bankers are mean't to be good with numbers and the country is the richest it's ever been...


    Oh hang on :eek:


    BODMAS is for equations...that is just a 'simple sum'.
  • allafixallafix Posts: 20,683
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    rob1973 wrote: »
    So you can't be trusted with figures then! :D

    I'm sorry but I'm with Floops, and don't give me this 'I'm an accountant' flim flam. Bankers are mean't to be good with numbers and the country is the richest it's ever been...


    Oh hang on :eek:


    BODMAS is for equations...that is just a 'simple sum'.
    BODMAS removes ambiguity, regardless of how simple or complex the expression (or sum) is. Fair enough if you like the idea of ambiguity of course. But if you insist it should be "left to right" for simple sums and BODMAS for complicated ones, you will also need to define the complexity level at which you switch from "left to right" to BODMAS. I suggest to you that any sum with a mixture of operators is complicated enough to need BODMAS.

    Floopy hijacked this thread and disappeared long ago, having had their fun. They also thought 40 x 0 = 40, are you in agreement with that too?
  • rob1973rob1973 Posts: 4,236
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    allafix wrote: »
    BODMAS removes ambiguity, regardless of how simple or complex the expression (or sum) is. Fair enough if you like the idea of ambiguity of course. But if you insist it should be "left to right" for simple sums and BODMAS for complicated ones, you will also need to define the complexity level at which you switch from "left to right" to BODMAS. I suggest to you that any sum with a mixture of operators is complicated enough to need BODMAS.

    Floopy hijacked this thread and disappeared long ago, having had their fun. They also thought 40 x 0 = 40, are you in agreement with that too?

    No I'm not completely as daft as Floops, but that sum, in the way it was presented equals 40.

    We have already agreed that mathematicians are lazy and don't like to use brackets. But I feel if it were an equation rather than a straight froward sum it would have been presented 3+(7x4). But here's the rub, how do we know where the lazy maths bods would have put the brackets? (3+7)x4? gives 40, 3+(7x4).

    As it stands it was presented 3+7x4. I understand it's a confusing issue and how it's percieved counts a lot. But I'm an engineer, I deal with numbers daily and I think you've got to look at the context it's delivered in. As it was delivered in (duming down but not for you) what is 3 plus 4 times 7 then it's a perfectly valid way of working it to get 40. That is kind of how my brain works when doing mental arithmetic. If I was sat down with pen and paper I'd probably think more about it.

    It's how it's been presented, as it's been presented by a quite obviously bone idle mathemetician then it's open to debate.

    I hope all that makes sense!

    And ETA, if people are getting both answers on 2 different calculators...that have been programmed with algorhythms developed my mathematicians then is there any wonder that there's so much bliddy confusion.

    Casio FX81! You're fired!! :D
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