Is there a convention on the order of scalar multiplication? I know there were questions before mine, but I would like to know if such distinction is culturally dependent.
This came from a news in Taiwan reporting a question appeared in a 2nd grade test. The question roughly translates as
A dozen of pencils has twelve pencils, and each pencil is sold at $\$8$. What is the total price?
- $8\times12$
- $12\times8$
- $8+12$
- $12+8$
(News report in Chinese, sorry)
And the only "correct"/"best" answer was $8\times12$. One teacher claimed that this is correct (and option 2 is not) because $8$ carries the unit and $12$ denotes the quantity. The teacher also claimed that $8$ as the multiplicand must goes before $12$ the multiplier, so the following sum should be written in this following way:
$$8+8+8+8+8+8+8+8+8+8+8+8 = 8\times12$$
And Wolfram MathWorld said otherwise. Instead of looking for a global convention, I would like to know is such convention affected by culture or language?
I have left elementary school long ago, and I cannot remember how I was taught.