用竖式计算.4.6+2.3 6.7+2.4 2,5﹣1.8 1.1﹣0.8 8.4﹣7.6 6.4+3.8.
(2.4×1.5-1.5)÷0.7
(3.2+3.2+3.2+3.2) ×2.5
+-
3600÷45×90
(2.5-2.5×0.6)÷0.4