1- = + = ×2= + = - =
18× = ÷6= ÷ = a-0.4a= + + + =
15.75÷2.1= 4.23÷1.2=
3.7×1.4×0.05 12.5×0.4×2.5×8
70分=小时。
①12.5×(8+0.8)
②+×
③+÷
④26﹣7.28﹣12.72
⑤5.8×4.1+5.9×5.8
⑥÷(+1.4×)