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用简便方法计算下面各题.1.8×0.9+0.185.4×0.68+3.4×2×0.4623.9-0.6×0.6-0.646.82÷4÷0.251.26÷(1.26×0.8)0.7777×0.7+0.1111×2.1.

题目详情
用简便方法计算下面各题.
1.8×0.9+0.18 5.4×0.68+3.4×2×0.46
23.9-0.6×0.6-0.64 6.82÷4÷0.25
1.26÷(1.26×0.8) 0.7777×0.7+0.1111×2.1.
▼优质解答
答案和解析
(1)1.8×0.9+0.18
=1.8×0.9+1.8×0.1
=1.8×(0.9+0.1)
=1.8×1
=1.8;
(2)5.4×0.68+3.4×2×0.46
=5.4×0.68+6.8×0.46
=5.4×0.68+0.68×4.6
=(5.4+4.6)×0.68
=10×0.68
=6.8;
(3)23.9-0.6×0.6-0.64
=23.9-0.36-0.64
=23.9-(0.36+0.64)
=23.9-1
=22.9;
(4)6.82÷4÷0.25
=6.82÷(4×0.25)
=6.82÷1
=6.82;
(5)1.26÷(1.26×0.8)
=1.26÷1.26÷0.8
=1÷0.8
=1.25;
(6)0.7777×0.7+0.1111×2.1
=0.1111×7×0.7+0.1111×2.1
=0.1111×4.9+0.1111×2.1
=0.1111×(4.9+2.1)
=0.1111×7
=0.7777.