196

watches the people with basic math skills fight to the death over the answer

Different compilers have robbed me of all trust in order-of-operations. If there's any possibility of ambiguity - it's going in parentheses. If something's fucky and I can't tell where, well, better parenthesize my equations, just in case.

There's quite a few calculators that get this wrong. In college, I found out that Casio calculators do things the right way, are affordable, and readily available. I stuck with it through the rest of my classes.

In some countries we're taught to treat implicit multiplications as a block, as if it was surrounded by parenthesis. Not sure what exactly this convention is called, but afaic this shit was never ambiguous here. It is a convention thing, there is no right or wrong as the convention needs to be given first. It is like arguing the spelling of color vs colour.

Please Excuse My Dear Aunt Sally, she downloaded a shitty ad-infested calculator from the Google Play store.

[...] the question is ambiguous. There is no right or wrong if there are different conflicting rules. The only ones who claim that there is one rule are the ones which are wrong!

https://people.math.harvard.edu/~knill/pedagogy/ambiguity/index.html

As youngsters, math students are drilled in a particular
convention for the "order of operations," which dictates the order thus:
parentheses, exponents, multiplication and division (to be treated
on equal footing, with ties broken by working from left to right), and
addition and subtraction (likewise of equal priority, with ties similarly
broken). Strict adherence to this elementary PEMDAS convention, I argued,
leads to only one answer: 16.

Nonetheless, many readers (including my editor), equally adherent to what
they regarded as the standard order of operations, strenuously insisted
the right answer was 1. What was going on? After reading through the
many comments on the article, I realized most of these respondents were
using a different (and more sophisticated) convention than the elementary
PEMDAS convention I had described in the article.

In this more sophisticated convention, which is often used in
algebra, implicit multiplication is given higher priority than explicit
multiplication or explicit division, in which those operations are written
explicitly with symbols like x * / or ÷. Under this more sophisticated
convention, the implicit multiplication in 2(2 + 2) is given higher
priority than the explicit division in 8÷2(2 + 2). In other words,
2(2+2) should be evaluated first. Doing so yields 8÷2(2 + 2) = 8÷8 = 1.
By the same rule, many commenters argued that the expression 8 ÷ 2(4)
was not synonymous with 8÷2x4, because the parentheses demanded immediate
resolution, thus giving 8÷8 = 1 again.

This convention is very reasonable, and I agree that the answer is 1
if we adhere to it. But it is not universally adopted.

I'm with the right answer here. / and * have same precedence and if you wanted to treat 2(2+2) as a single unit, you should have written it like (2*(2+2)).

People keep debating over this stuff. I have a simpler solution. Math is not real.

this is why I never use ÷ (or more realistically "/") without explicit brackets denoting order of operations.

this comment section illustrates perfectly why i hate maths so much lmao

love ambiguous, confusing rules nobody can even agree on!

Just write it out as a fraction and avoid all the confusion

16

The calculator is correct

The problem is that there's no "external" parentheses to really tell us which is right: (8 / 2) * 4 or 8 / (2 * 4)

The amount of comments here shows how much debate this "simple" thing generates

For anyone like me who has math as their worst subject: PEMDAS.

PEMDAS is an acronym used to mention the order of operations to be followed while solving expressions having multiple operations. PEMDAS stands for P- Parentheses, E- Exponents, M- Multiplication, D- Division, A- Addition, and S- Subtraction.

So we gotta do it in the proper order. And remember, if the number is written like 2(3) then its multiplication, as if it was written 2 x 3 or 2 * 3.

So we read 8/2(2+2) and need to do the following;

• Read the Parentheses of (2 + 2) and follow the order of operations within them, which gets us 4.
• Then we do 2(4) which is the same as 2 x 4 which is 8
• 8 / 8 is 1.

The answer is 1. The old calculator is correct, the phone app which has ads backed into it for a thing that all computers were invented to do is inaccurate.

People in this thread need to watch this: https://youtu.be/lLCDca6dYpA

The correct answer is 16. Multiplication and Division happen at the same level of priority, and are evaluated left-to-right.

Left is correct; implicit multiplication takes precedence over explicit multiplication or division.