should math be read from left to right or from right to left, or read from the direction the math makes most sense, stay inside the other existing rules?
one can easily set up nonorthodox equations that are wrong if read wrong direction, so there must be direction rules?
almost any language have rules from what side one must read for it to make sense.
No doubt you are asking a deeper question, but as a start, this comes to mind about the Order of Operations:
"First, we solve any operations inside of parentheses or brackets. Second, we solve any exponents. Third, we solve all multiplication and division from left to right. Fourth, we solve all addition and subtraction from left to right."
so it is not strictly left to right no matter the operations; instead it is sequential and keeps looping back until each operation has been completed.
On texts in Chinese or Arabic, for example, it would be a very good question too though.