I have read and heard in many places that multiplication and division are of equal precedence. So what is the value of:
$$
80 \div 10 \times 2
$$
Is it
$$(80 \div 10) \times 2 = 16$$
or
$$
80 \div (10 \times 2) = 4
$$
? The answer here seems to be that by convention we operate from left-to-right, so the first solution is correct. But I would have thought we should get the same answer either way if multiplication and division are of equal precedence. Isn't the whole point of operator precedence to resolve expressions that would otherwise have more than one solution?
For example, people also say that addition and subtraction are the same level of precedence, but no such ambiguity exists there:
$$
80 + 10 – 2 = (80 + 10) – 2 = 80 + (10 – 2) = 88
$$
So what is meant when people say that multiplication and division have the same precedence?
Best Answer
When there is equal precedence, the standard thing to do is to work from left to right. Hence $$80/10\times 2 = (80/10)\times2=16. $$
It should be noted that this is not completely universal, i.e. some programming languages don't do it this way, as far as I know. Anyway, it doesn't really matter that much because no one actually writes $80/10\times2$, instead they write $(80/10)\times2$ to remove any ambiguity.