问题 解答题 口算、心算.1+2.5=0.6+0.4=0.9-0.4=1-0.03=12-0.4=0.36+7=0.83+0.9=7.2+1.2= 答案 1+2.5=3.50.6+0.4=10.9-0.4=0.51-0.03=0.9712-0.4=11.60.36+7=7.360.83+0.9=1.737.2+1.2=8.4