What's the answer to this very basic maths problem?
- Thread starter Diddums x
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I think the point is just to make ppl say 26 so they look stupid like I did.
Multiplication before addition.
Soldato
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I went on to do A level and further A level maths, but I totally forgot about BODMAS!
I still managed to get it as -11 though.
I processed (-7-1) first which gave me -8
Then 16 over -8 gave me -2
Then it's 7 minus 2 minus 16 gave me -11
I still managed to get it as -11 though.
I processed (-7-1) first which gave me -8
Then 16 over -8 gave me -2
Then it's 7 minus 2 minus 16 gave me -11
Nor me.
Had no clue what people where in about the first time I heard it mentioned.
That's that I got, wasn't sure if I was right though.
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It's caught you out, there's a multiplication in the last line
Wrong, this is why there are so many rage inducing Facebook math riddles designed specifically to exploit the different ways that different generations will work things out due to the ways maths has changed over the years.NO!
/snip
It is Mathematics. It does not age. There are no "multiple answers". (Except where you find the square root of positive numbers, anyway).
A simple example is 6÷2(1+2)
The correct answer to above today is 9 and that is the answer most people who can do math and most calculators will give, however most older people and old calculators will answer 1, which was the correct answer using the previous accepted system.
I didn't even notice that last one was an 'x' rather than a '+'.
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AFAIK there can be conventions that would mean that the juxtaposition of the 2 next to the brackets takes precedence so (using a less silly example) say you write 1/ 2(cos x) that would be read as 1/ (2(cos x)) whereas if you write 1/2 (cos x) that would be read as (1/2)(cos x) though I don't think that is what you're referring to.
the example you've given is basically the same issue as the one we had a thread about a few years ago - it is just a silly thing posted on Facebook to start an argument and is deliberately meant to be confusing... the basic rules of arithmetic haven't changed though so I don't think you're correct to quote @h4rm0ny and state 'wrong'
If you read the post you quoted I specifically cited an equation to which the accepted correct answer has changed with time as the accepted conventions have changed (despite him claiming this has never happened) in order to refute his erroneous reply to me.
It's an example of how changing usage of mathematics conventions over time has changed the answer deemed "correct" by the masses. The reason it causes arguments is because many older people and even calculators will still give the now depreciated answer. Like I explained.
I did read that post you quoted thanks. Perhaps you can explain how it has changed over time? At what point in time did it change?
I suspect you're just making things up based on some Facebook chat/confusion over a silly question that has been posted in order to cause confusion but am willing to be corrected.
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the calculator has precedence doesn't it ?
Soldato
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Well i saw the 2nd post answer being -11
If you write it like that i have to do the following
7+16 =23
-7-1 = -8
23/-8 = -2.875
-2.875-16 =
-18.875
Now if you want me to answer -11 i would change the question from the above to
(7 + ((16 / (-7-1)))-16
Then it goes
-7-1 = -8
16/-8 = -2
7+-2= 5
5-16=-11
In fact the first example i could do it differently too,
I.e. 7+16
----------------
(-7-1)-16
In which case the answer is 23/-24 = -0.9????
Or maybe its because the only time i ever use any maths is when using excel to make spreadsheets of calculations for various reasons?
A friend of mine consistently posts ridiculous answers on every stupid maths thing that turns up on Facebook.
Simple calculators that calculate each stage as a separate operation as you enter it will give you the answer 1. That doesn't mean that they're correct. It means that they are designed to do one operation at a time. You're not actually entering the whole thing at once. Every time you press '+' or 'x' that's a short-hand for pressing equals and then pressing the new operator on the resulting answer. Microsoft Windows' calculator does this. But it should also be obvious to the user that this is what is happening because it displays each new result as you go along.
A scientific calculator will allow you to enter the full sum before pressing equals and getting the final result. And it will give you the answer 9, as I did. There's no "new way to do it", just basic calculators and people not understanding that they're entering multiple sums, not one.
When did this ever equal 1?
General non-scientific calulators will not follow order of operation - modern or old. It's just the way they are.