plus, 2 plus 3 equals to 5
減: subtract, 如:2 substracted from 5 is 3
minus, 如: 5 minus 2 is 3.
乘:multiply , 如: multiply 2 by 3
times 如: 3 times 2 is 6
除:divide, 如, 6 divided by 3 equals to 2