Are the names and symbols for common mathematical operators the same in every language? Do all human languages that have arithmetic use +, -, ×, ÷, and ^?
How about sin, cos, tan, asin, acos, and atan?
 A: Some differences I've noticed are the following (this list is by no means exhaustive):


*

*In some languages they use $\times$ for multiplication, some languages use $\cdot$.

*Division might be either of $\div$, $/$ or $:$, depending on where you are. Some people use $\div$ as a subtraction symbol.

*Dividing large numbers into readable chunks is done differently too. Some places a million and a quarter is written $1,\!000,\!000.25$. Some places it's $1\:000\:000,\!25$. In east Asia, they don't group digits three and three at all, but rather four and four.
A: There are human languages that have arithmetic but their users still do not make use of any formal symbols for arithmetic operations (or even numbers).
You mentioned internationalizing an application so two more things may be useful:
1)in some languages it is common to use dot "." in decimals, like in "1.5", while in other languages it is common to use comma ",", like in "1,5".
2) ${\bf tg}$ is in some languages used instead of ${\bf tan}$, and ${\bf arcsin}$ instead of ${\bf asin}$, similarly for other functions.
A: In Dutch, for the trigonometric and cyclometric functions, you will see


*

*$\text{tg}$ instead of $\tan$, although $\tan$ is quite common

*$\text{Bgtg}$, $\text{Bgtan}$, $\text{bgtan}$ instead of $\arctan$ or $\text{atan}$ because "arc" is "boog" in Dutch. Same for $\arcsin$ and the like.


Some other differences


*

*$\text{ln}$ for the natural logarithm. This is probably not unusual but some English texts will use $\log$ for the natural logarithm.

*One million is written $1.000.000$, a half in decimals is $0,5$. So the use of dots and commas is inverted w.r.t. English. This is true in most continental European languages by the way.

