3.8×13+8.7×38[0.85+(9.25+0.65)÷0.2]×20
93.6÷[(54.8+45.2)×0.06]
0.8+0.55+1.2-0.45
+-
1--
口算。+= -= += - +=0.63×1000= 0. 75-0.25= 0.07+0.03= 0. 9÷0.03= 0.4×0.8=