jarenault said:
ScottM said:
The only answer to the original question is that, regardless of BODMAS and whatnot, nobody who wasn't an idiot would genuinely write out a sum like that in this way. You would use parentheses for clarity.
The only reason other than stupidity to write out a sum in such a way is to try to deliberately confuse people in a pretty unimaginative sort of way. It's not a clever or revealing puzzle, it's just a waste of time.
It reminds me of this:
http://xkcd.com/169/
This type of thinking is the reason that so many people get it wrong. Parentheses are ONLY used in very basic math problems because people don't get it otherwise. Parentheses are for spoon feeding math problems. They are required in complex problems (I use complex loosely) to signify block calculation, but they are not required and not used in the above problem..... other than in situations where the students/people require them to be in order to follow what's going on. It's a learning curve.
The idiots aren't the ones who don't feel the need to use pointless parentheses, believe it or not.
I respectfully disagree. There's nothing "intelligent" about BODMAS. It's an arbitrary rule. It's not correct in an a priori, objective, sense. It's just a convention.
Even just from a utilitarian perspective it's of little use. It's clear from these stupid Facebook threads that it's not widely understood. Therefore it makes no pragmatic sense to rely on people's understanding. There are simpler and more intuitive ways to express calculations.
The calculation is badly communicated, allowing the person who posts it to get a cheap gloat when it's misunderstood.
BODMAS is one of these things, like cm^3 instead of ml, that only ever seems to be used in schools.
I disagree with everything other than the reason for it being posted on facebook. It is most definitely to take advantage of the average persons understanding of mathematics.
However, it is only poorly communicated in a sense that not everyone will understand the practices involved in solving it. To make it immediately solvable by everyone able to add, subtract and multiply the figures in the equation, brackets could be used in order to point them in the right direction on how to correctly solve it.
BODMAS is used in mathematics. It's a rule of mathematics. Nothing more, nothing less. I remember VERY little of the principles and rules in math, I don't use them in my daily life in order to remember them. The only reason I remember BODMAS is because of puzzles like the one I posted coming up time and time again. I use basic algebra every now and again, as well as a reasonable amount of basic Trig.
Because we don't use mathematics rules and principles doesn't mean that they don't exist and aren't correct.
In this instance the answer IS 12, there is no argument. The reason for the question and the layout of it is, however, entirely debatable.... but I do agree with your reasoning in that regard..