9/3(4-1) another one of those stupid maths thing

People keep saying it's 1 cos 4-1 = 3 and 3 * 3 = 9 and 9/9 = 1, which is all true but if that were the correct method wouldn't it need to be 9/(3(4-1)).

TSR needs to install something to detect threads with anything of the form a/b(c+d) in the title, stamp the words AMBIGUOUS NOTATION over any other mention it and then print out a massive hand to slap the OP with.

This thread will soon be locked and deleted, making my post redundant, so I won't put any effort into justifying my claim that the notation is ambiguous, but it is. You're wrong if you claim that it's definitely and unquestionably one answer or the other. There are implicit brackets, meaning that either a/b(c+d) = (a/b)(c+d), or that a/b(c+d) = a/(b(c+d)). That is, $\frac{a}{b}(c+d)$ or $\frac{a}{b(c+d)}$. It's not made clear from the notation which it is, and you can't decide conclusively without making up a non-standard rule. This is why people who don't know any better go with their first instinct and the battle commences.

The real question is this. Why won't it stop?!

TSR needs to install something to detect threads with anything of the form a/b(c+d) in the title, stamp the words AMBIGUOUS NOTATION over any other mention it and then print out a massive hand to slap the OP with.

This thread will soon be locked and deleted, making my post redundant, so I won't put any effort into justifying my claim that the notation is ambiguous, but it is. You're wrong if you claim that it's definitely and unquestionably one answer or the other. There are implicit brackets, meaning that either a/b(c+d) = (a/b)(c+d), or that a/b(c+d) = a/(b(c+d)). That is, $\frac{a}{b}(c+d)$ or $\frac{a}{b(c+d)}$. It's not made clear from the notation which it is, and you can't decide conclusively without making up a non-standard rule (e.g. 'work from left to right'). This is why people who don't know any better go with their first instinct and the battle commences.

The real question is this. Why won't it stop?!

No, you are wrong, it is not ambiguous, multiplication and division happen left to right. This is a standard rule and is also how computers operate.

No, you are wrong, it is not ambiguous, multiplication and division happen left to right. This is a standard rule and is also how computers operate.

Okay I'm sorry I admit I was wrong, can you delete this thread now I'm fed up with the negs.

No, that isn't a standard rule, it's a method used to make Year 8 pupils ask less questions when presented with something like 2×3×6×12 to evaluate, and the rule doesn't exist outside of the world of KS3 maths.

Notation serves to make our lives easier, and any rules which refer only to notation (e.g. 'work left to right') are not mathematical rules, they're guidelines for notation and are open to interpretation depending on what notation you use. In fact, if I wrote 1+x/3+x I'd expect it to be interpreted as $\frac{1+x}{3+x}$ instead of $1 + \frac{x}{3} +x$.

"9/3(4-1)" is written ambiguously; it can have no evaluation until it is clarified.



Well I can't delete it