I looked at what he'd given me and did a quick subtraction.我看着他给我的东西，快速做了个减法。The difference is found by subtraction.用减法得出差额.The plus sign is used in addition and the minus is used in subtraction.加号用于加法;减号用于减法....
The plus sign is used in addition and the minus is used in subtraction.加号用于加法;减号用于减法....using concrete objects to teach addition and subtraction.用实物来教加减法There will be simple tests in addition, subtraction, multiplication...