用简便方法计算.1.7-0.81+1.3-0.19  
来源:学生作业帮 编辑:大师作文网作业帮 分类:数学作业 时间:2024/09/21 05:26:44
用简便方法计算. 1.7-0.81+1.3-0.19 | 0.25×32×1.25 |
(1)1.7-0.81+1.3-0.19 =(1.7+1.3)-(0.81+0.19) =3-1 =2; (2)0.25×32×1.25 =0.25×(4×8)×1.25 =(0.25×4)×(8×1.25) =1×10 =10; (3) 16 25×7+ 7 25×9 = 16 25×7+ 9 25×7 =( 16 25+ 9 25)×7 =1×7 =7.
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