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简便计算. 15.6789÷20÷5 2.8×23.4+11.1×57.6+6.54×28 34.5×8.23-34.5

来源:学生作业帮 编辑:搜搜做题作业网作业帮 分类:数学作业 时间:2024/05/02 08:42:03
简便计算.
15.6789÷20÷5 2.8×23.4+11.1×57.6+6.54×28
34.5×8.23-34.5+2.77×34.5 0.9999×0.7+0.1111×2.7.
简便计算. 15.6789÷20÷5 2.8×23.4+11.1×57.6+6.54×28 34.5×8.23-34.5
(1)15.6789÷20÷5,
=15.6789÷(20×5),
=15.6789÷100,
=0.156789;
(2)2.8×23.4+11.1×57.6+6.54×28,
=28×2.34+6.54×28+11.1×57.6,
=28×(2.34+6.54)+11.1×57.6,
=28×8.88+11.1×57.6,
=28×8×1.11+1.11×576,
=224×1.11+1.11×576,
=(224+576)×1.11,
=800×1.11,
=888;
(3)34.5×8.23-34.5+2.77×34.5,
=34.5×(8.23-1+2.77),
=34.5×10,
=345;
(4)0.9999×0.7+0.1111×2.7,
=0.1111×9×0.7+0.1111×2.7,
=0.1111×6.3+0.1111×2.7,
=0.1111×(6.3+2.7),
=0.1111×9,
=0.9999.