用竖式计算.7.4+12.86= 20﹣5.674= 141.2﹣48.98=102+4.36= 32.15﹣27.45=验算: 12.9+5.01=验算:
计算下面各题,能简便计算的要简便计算.(1)5.27﹣1.98﹣0.02(2)3.2×5.7+6.8×5.7(3)8.1÷(0.9×0.3)(4)〔1.6+19.2÷(22﹣21.7)〕×5.
用竖式计算.
(1)计算+4﹣ (2)计算:(2.4﹣)÷﹣×2.3 (3)解方程:5:x=3:6 (4)已知a:b=3:4,b:c=3:5,求a:b:c.
竖式计算.
脱式计算