Rummy Posted April 22, 2007 Author Posted April 22, 2007 I've always been taught this rule: brackets first, then to what power it is, then divide and multiply and lastly addition and subtraction. Also, go from left to right. Addition and subtraction are equal, which means that you should get 197. I'd never heard of BODMAS before and had to look it up. Weird thing, especially since it seems to imply addition and subtraction are not equal. It's basically what you've been taught there. I say I was taught it(BODMAS), it was covered for about 20 minutes by our teacher in a year 9 maths lesson, but it stuck in my mind since then, and was never brought up again in all my subsequent maths learning. Having said that, had I seen the line 2-5+200, I would work it out to be 197. So it's quite an mystery how I can see this from both sides and think that both are right and both are wrong. The problem with calculators and programs on computers apparently is that they have different order of operations, which is why the windows calculator will give both 140 and 197 depending on what mode it is in(wikipedia pointed this out to me). the only way you can get 140 = 2*(20+(5*10)). I'd love to know how you managed to input that. 7 x 20 maybe? (the 7 comes from doing the 2 - 5 + 10, and then the *20)
Ellmeister Posted April 22, 2007 Posted April 22, 2007 Hahaha this is awesome. After reading this, I've realised that no-one will ever agree. Also is BODMAS the same as BIDMAS (what I've been taught) which is, Brackets Indices Divide Multiply Addition Subtraction? I get -203, but when looking at other people's methods I get their answers to. Surely the equation is seriously lacking brackets like erm i think Shorty said earlier.
conzer16 Posted April 22, 2007 Posted April 22, 2007 Hahaha this is awesome.Also is BODMAS the same as BIDMAS (what I've been taught) which is, Brackets Indices Divide Multiply Addition Subtraction?. Yeah I was taught BOMDAS (Mulitply + Divide reversed) which is the same. I = Indices, O = Order which is another name for Indices.
Rummy Posted April 22, 2007 Author Posted April 22, 2007 Hahaha this is awesome. After reading this, I've realised that no-one will ever agree. Also is BODMAS the same as BIDMAS (what I've been taught) which is, Brackets Indices Divide Multiply Addition Subtraction? I get -203, but when looking at other people's methods I get their answers to. Surely the equation is seriously lacking brackets like erm i think Shorty said earlier. But if someone asked you to solve the sum 2-5+200=?, what answer would you come up with then?
The fish Posted April 22, 2007 Posted April 22, 2007 As far as I can tell, what would really make the maths in the first post better would be some brackets...
Ellmeister Posted April 22, 2007 Posted April 22, 2007 Well firstly its not 2-5+200=? because thats considering I would simply multiply 10 X 20 first. In my own opinion, I would say 2-5+10*20=197. just looking at it and giving the answer that I would come up with without taking into consideration all these possible methods through BIDMAS. confusing.
The fish Posted April 22, 2007 Posted April 22, 2007 To be honest, BODMAS (or BIDMAS) are both bollocks in my eyes. Brackets should always be used in this kinda of equation, and adding and subtracting should be done simultaneously, as should multiplying and dividing. It's all designed to give students something else to do in class and revise. Talking of revision, I have a AS-maths paper to do...
Rummy Posted April 22, 2007 Author Posted April 22, 2007 Well firstly its not 2-5+200=? because thats considering I would simply multiply 10 X 20 first. In my own opinion, I would say 2-5+10*20=197. just looking at it and giving the answer that I would come up with without taking into consideration all these possible methods through BIDMAS. confusing. You assume to much, I was posing that as a different question to highlight the thinking that leads to the -203, or rather the thinking that should lead to the 197. When did people here learn about BODMAS/BIDMAS/whatever? I feel like I've learnt a horrible lie, but always knew it was wrong anyway so it didn't affect anything.
MoogleViper Posted April 22, 2007 Posted April 22, 2007 Our teacher once mentioned BODMAS in year eight. Basically he just said, (well mumbled in the most horrible geordie accent), "Brackets, Order, Division, Multiply, Addition, Subtraction." And that was it.
Shino Posted April 22, 2007 Posted April 22, 2007 I don't get this thread, and whats a BODMAS? Edit: Moogleviper just said it.
Zell Posted April 22, 2007 Posted April 22, 2007 People, there's no "opinion" on the matter. The answer is 197. Anyone who thinks differently needs to brush up on their maths.
Ginger_Chris Posted April 22, 2007 Posted April 22, 2007 People, there's no "opinion" on the matter. The answer is 197. Anyone who thinks differently needs to brush up on their maths. Well said, sigh, I can't believe we even had this conversation. It really put a major downer on the education system when extremely simple arithmetic is performed incorrectly. I would even consider it maths.
Shino Posted April 22, 2007 Posted April 22, 2007 Well said, sigh, I can't believe we even had this conversation. It really put a major downer on the education system when extremely simple arithmetic is performed incorrectly. I would even consider it maths. Well, it out of the context, the context being 4chan. A more recurring and interesting one is: 1/1=1 -1/-1=1 0/1=0 0/0=? Yes, I know its undefined, but at least its more interesting than this.
DCK Posted April 23, 2007 Posted April 23, 2007 BODMAS or whatever name you give it tells you you should add/substract in the same order it is in the calculation. 2 - 5 + 20 x 10 = 2 - 5 + 200 = -3 + 200 = 197 Come on.
Cube Posted April 23, 2007 Posted April 23, 2007 Our teacher once mentioned BODMAS in year eight. Basically he just said, (well mumbled in the most horrible geordie accent), "Brackets, Order, Division, Multiply, Addition, Subtraction." And that was it. The thing is, subtraction doesn't actually exist. The teaching of Addition, Subtraction, Multiplication and Division as the very first thing in maths (bar counting) doesn't help this at all. Subtraction is Addition.
Shino Posted April 23, 2007 Posted April 23, 2007 The thing is, subtraction doesn't actually exist. The teaching of Addition, Subtraction, Multiplication and Division as the very first thing in maths (bar counting) doesn't help this at all. Subtraction is Addition. Neither does division.
Supergrunch Posted April 23, 2007 Posted April 23, 2007 Ginger Chris speaks the truth, as he usually does with such matters. And there is no need to put in brackets, as the order of operations is clear. Also, this is boring.
MoogleViper Posted April 23, 2007 Posted April 23, 2007 i also like 0^0. Isn't it 1? I was taught that anything to the power of 0 is 1.
Rummy Posted April 23, 2007 Author Posted April 23, 2007 i also like 0^0. It makes me think of an owl.
Zell Posted April 23, 2007 Posted April 23, 2007 Something more interesting: x = 1 x^2 = x x^2 -1 = x - 1 (x + 1)(x - 1) = x -1 x + 1 = 1 x = 0 Therefore 1 = 0
Rummy Posted April 23, 2007 Author Posted April 23, 2007 Surely the dividing by x-1 is dividing by 0, which you aren't supposed to do?
Goron_3 Posted April 23, 2007 Posted April 23, 2007 If you don't get 197 you're an idiot. Even i can get this right.
KingJoe Posted April 23, 2007 Posted April 23, 2007 Bodmas, Bidmas and Pemdas are exactly the same thing. They are a way of remembering an order of operations, and they aren't perfect. I've come across this point in my maths lessons (I'm a maths teacher) and we ended up discussing the idea of conventions in maths and the fact that each object was seperate (i.e. you would add the 200 before subtracting). Can be an interesting discussion can lead to me going nuts and just getting pupils to think of add/subtract as the same, multiply/didvide as the same and getting them to rearrange positives on the left, negatives on the right. It all depends whether I'm teaching for understanding or to pass exams to be honest. And well spotted rummy. 0^0 is undefined, no? because it's equivalent to 0^1/0^1 ? Subtraction is not addition, they are different. Strongly related but definately different (one is commutative and one isn't, for starters).
AshMat Posted April 23, 2007 Posted April 23, 2007 Well, it out of the context, the context being 4chan. A more recurring and interesting one is: 1/1=1 -1/-1=1 0/1=0 0/0=? Yes, I know its undefined, but at least its more interesting than this. DIVIDE IT BY ZERO!
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