That's why parenthesis are important =)Thus why Left-to-Right order standardization among operators of equal precedence is important.
48/(2*12) =/= (48/2)*12
There's no "left to right" rule in math...
But then you get to some higher level stuff where they require you to think backwards of what they taught you in high school, and you get stuck because you high school teacher just followed the textbook and taught you to simply follow the algorithms without thinking. Thinking is the key, not learning algorithms for solving problems.
Says who?
That's exactly why standards are important and being clear when writing an equation is important.
Assuming the problem is:
48
_____
2 * 12
Is wrong. There is no reason to assume implied parentheses around the (2*12).
@Hraklea I agree, I'm a huge fan of parentheses. I was always taught in school to do left-to-right, but you're probably right not to assume that's a world-wide concept. Better safe than sorry is my motto
Last edited by apinksquash; 2011-04-19 at 08:42 PM.
Yes, I was wrong in that regard. Math is beautiful, the lines are very clear. I always read it as a multiplication of a fraction (i.e. 48 * 1 over what comes after wards, thus I read it with implied parentheses, which is a big jump I admit. This jump is equivalent to left to right evaluation rule come to think of it)
Last edited by Knuffelbert; 2011-04-19 at 08:45 PM.
I'm currently taking real analysis and modern algebra. Not sure what higher level stuff you are talking about that requires backwards thinking that breaks order of operations. Maybe in graduate school, but that's why I asked for an example. I was somewhat looking for an example of this "high level stuff"
Grad school to the rescue: group theory can get fancy. It doesn't "break" order of operations, but you have a completely different kind of algebra, so you need different rules. edit: OK, you know that if you are taking modern algebra (which I will take to mean abtract algebra).
@hax: I appreciate where you're going with the creativity bit, and I agree that following a formula does not lead to understanding, but I think it's odd that you are taking it out on order of operations. It is the standardized way of communicating math.
Last edited by Auloria; 2011-04-19 at 10:41 PM.
PEMDAS. Parenthesis, Exponents, Multiplication, Division, Addition, Subtraction.
If you have a hard time remembering the order. Just say:
Please Excuse My Dear Aunt Sally
if you don't have an Aunt named Sally
Please Excuse My Dumb Ass Sister
if you still can't remember it, then there's nothing else to do :x.
Yup. They come in handy for stuff like busywork mathematics, solving otherwise nigh-impossible integrals, graphing and loads of other stuff. The rest of your comments don't seem to give any particular insight.
@Tarantism - The acceptance of whether or not there is an implied pair of brackets/parenthesis is the issue at hand for that particular problem. Writing this:
48
______
2(9+3)
To mean this:
48/2 * (9+3)
Is a rather poor and very confusing way to do so. The thing is, textbooks, mathematicians and computer programs all write fractions this way at some point or another, and it's often intended that there are implied brackets/paranthesis. A lot of calculators and applets account for this and make the calculation as such, so they're not wrong in that sense, because they followed their order of operations correctly. That's why there's a lot of confusion on that particular subject. That's also why I didn't want to go further than just the required math for engineering. Past that it gets into all this theory stuff that confuses and pisses me off, heh.
BODMAS
B - Brackets (Parenthesis)
O - Of
D - Division
M - Multiplication
A - Addition
S - Subtraction
Try this.
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