的 是;40千克比千克少 。
÷ = ×0.6= 5÷5÷ = × =
4÷ = ÷0.6= ×50%= 3× ÷3× =
① × + ÷4
② ×[( + )÷ ]
③( + )×5×7
④21.38-( +1.38)
⑤ +0.65÷1.3-30%
⑥6.8-3.9× +2.8