问题
解答题
用简便方法计算下列各题.
20×0.4+0.6×0.20
(12×5)×(0.2×24)
15×0.4+8×0.75.
答案
(1)20×0.4+0.6×0.20
=2×4+0.06×2
=(4+0.06)×2
=4.06×2
=8.12;
(2)(12×5)×(0.2×24)
=12×(5×0.2)×24
=12×1×24
=288;
(3)15×0.4+8×0.75
=6+6
=12.
用简便方法计算下列各题.
20×0.4+0.6×0.20
(12×5)×(0.2×24)
15×0.4+8×0.75.
(1)20×0.4+0.6×0.20
=2×4+0.06×2
=(4+0.06)×2
=4.06×2
=8.12;
(2)(12×5)×(0.2×24)
=12×(5×0.2)×24
=12×1×24
=288;
(3)15×0.4+8×0.75
=6+6
=12.