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下面计算的对吗?对的打对,不对的请改正.

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/05/14 05:01:29
下面计算的对吗?对的打对,不对的请改正.
2.5×7.5×0.5 8.5×99
=2.5×(7.5-7.5)×0.5 =8.5×(99+1)
=2.5×0×0.5 =8.5×100
=0 ( ) =850 ( )
12.5×3.2×0.25 1.25×(8+0.8)
=(12.5×0.8)×(4×0.25) =1.25×8+0.8
=10×1 =10+0.8
=10 ( ) =10.8 ( )

( ) ( )
还要改正啊
1 错 2 错 3 对 4错
1订2.5×7.5×0.5
=2.5×4×2×7.5×0.5/(2×4)
=10×1×7.5/8
=75/8
=9.375
2订8.5×99
=8.5×(100-1)
=8.5×100-8.5×1
=850-8.5
=841.5
4订1.25×(8+0.8)
=1.25×8+1.25×0.8
=10+1
=11