Are percentages in addition non-commutative?

[Seiryuu]

I recently came across this equation on social media:

At first I thought it would the answer after simplifying the equation would be  and thus 12 + 6 = 18, but inputting into my calculator gets me 8 instead. Inputting the reverse () gives me my expected answer of 18. Is it an inherent property of percentages to take what's to the left?

[swansont]

4 minutes ago, Seiryuu said:

I recently came across this equation on social media:

At first I thought it would the answer after simplifying the equation would be  and thus 12 + 6 = 18, but inputting into my calculator gets me 8 instead. Inputting the reverse () gives me my expected answer of 18. Is it an inherent property of percentages to take what's to the left?

There is an order of operations in math (you multiply and divide first), but perhaps you should use an example that isn’t nonsensical. Adding numbers and percentages, for example. How does 200% + 6 become 12 + 6? 200% of what?

[Seiryuu]

3 minutes ago, swansont said:

There is an order of operations in math (you multiply and divide first), but perhaps you should use an example that isn’t nonsensical. Adding numbers and percentages, for example. How does 200% + 6 become 12 + 6? 200% of what?

That's the equation as is; it was asking what the value would be.

That's what I'm asking. By default on a calculator percentages are computed to be relative to 1, so I can see how 200% would turn into 2. I was under the impression that 200% + 6 is the same as 6 + 200%. Is this not the case?

[swansont]

1 minute ago, Seiryuu said:

That's the equation as is; it was asking what the value would be.

That's what I'm asking. By default on a calculator percentages are computed to be relative to 1, so I can see how 200% would turn into 2. I was under the impression that 200% + 6 is the same as 6 + 200%. Is this not the case?

6 + 200% makes no sense to me. This sounds like an example made up by someone who doesn’t understand math, and is just throwing some numerical terms together.

200% of some number would make sense, but that’s multiplicative, not additive 

[studiot]

14 hours ago, Seiryuu said:

I recently came across this equation on social media:

At first I thought it would the answer after simplifying the equation would be  and thus 12 + 6 = 18, but inputting into my calculator gets me 8 instead. Inputting the reverse () gives me my expected answer of 18. Is it an inherent property of percentages to take what's to the left?

I note that you have been a member longer than I have and have contributed to several threads in your science area of Biology / Chemistry, and have good knowledge of the terminology in these areas.

 

So let me start by pointing out that

is not an equation.

It is (an attempt at) a mathematical statement or expression.

An equation is a statement or expression containing an equals sign.

 

Not only does it fail to be an equation, it also fails to be a proper or valid expression since the connectives (add, multiply and divide) employed are all meant to form combinations of the objects referenced (200%, 4,3 and 2).

 

The 200% object is of a different type from the other 3 and not conformable to combination with them.

 

Sometimes objects of dissimilar types can be combined (as with complex numbers) but generally the rule is that dissimilar objects cannot be combined.

 

As a biologist you will be familiar with the idea of 'counts'.

 

I cannot tell without context whether the 4, 3 and 2 are simply numbers or actually counts.