:平均每位运动员用时多长?(得数保留两位小数)
①3.6+5.4= ②6.7-3.8= ③0.8÷2= ④6×2.5=
⑤102×25= ⑥ = ⑦3- = ⑧ =
×8= 1-0× =
599÷6≈ 52-32= 0.75÷15=
68×51≈