乘：A kind of operation,expressed as“×”
积：The result of“乘"
除（以）：A kind of operation,expressed as“÷”
商：The result of“除"
For example：
3×5=15
3乘5=15,15 is the”积"
15÷3=5
15除以3=5（OR 3除15=5）,5 is the ”商"