直接写出得数.0.2+0.5= 11×50= 8.4﹣3= 20×40= 1+1.9= 3.9﹣2.9=45×3= 70×70= 4﹣3.98= 200×30= 50×60 13.2﹣5.2=
+-
1--
口算。+= -= += - +=0.63×1000= 0. 75-0.25= 0.07+0.03= 0. 9÷0.03= 0.4×0.8=
×= ÷3=÷= -=3÷15= +0.25=1÷= 85%-15%=10÷10%= 5×÷5×=
脱式计算下面各题。4÷-0.6 ×÷(+)÷ ÷[1÷(-)]