Wikipedia上也讲了，由于语言的区别，日本的multiplier和multiplicand的顺序和英文的相反。

The multiplication of whole numbers may be thought as a repeated addition; that is, the multiplication of two numbers is equivalent to adding as many copies of one of them, the multiplicand, as the value of the other one, the multiplier. Normally, the multiplier is written first and multiplicand second,^[1] though this can vary, especially in languages with different grammatical structures, such as Japanese, Japanese elementary schools teach writing the multiplicand first, and answers that reverse that order are marked as incorrect.

日语和中文在排序上都是一致的，比如地址都是由大到小，所以中国的传统也是被乘数在前，乘数在后。

近些年来，唯美国马首是瞻，用美国的方法多起来了，和传统中文语言顺序的起了冲突，主流的中国教材已经避免谈被乘数、乘数的问题。美国由于今年Common Core的兴起，反而强调multiplicand, multiplier了。