第五单元自主检测
1: 0.5 0.3 3.9 0.48
0.021 8 40 0.6
2: (1)0.0111 (2) 1.2 (3)9 竖式略
3: (1) 5×7.26÷1.2
= 36.3÷1.2
= 30.25
(2) 0.25×1.58×4
= 0.25×4×1.58
= 1×1.58
= 1.58
(3)78.5×0.8-8.5×0.8
= 0.8×(78.5-8.5)
= 0.8×70
= 56
(4)99×1.24+1.24
= 1.24×(99+1)
= 1.24×100
= 124
(5)4.35+0.17+0.65+0.83
= (4.35+0.65)+(0.17+0.83)
= 5+1
= 6
(6)3.6÷[0.25×(17.3+30.7)]
= 3.6÷[0.25×48]
= 3.6÷(0.25×4×12)
= 3.6÷12
= 0.3
4: ⑴ A ⑵ B ⑶ C