2.5×56+4.5×65 简算

发布网友 发布时间：2024-10-24 13:07

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热心网友 时间：2024-10-24 23:42

(2.5+4.5)×56×65肯定是错误的.

2.5×56+4.5×65
=2.5×56+45×6.5
= 2.5×56+44×6.5+6.5
=2.5×56+44×(2.5+4)+6.5
=2.5×56+44×2.5+44×4+6.5
=2.5×(56+44)+44×4+6.5
=2.5×100+44×4+6.5
=250+176+6.5
=426+6.5
=432.5
或者说:
=2.5×4×14+292.5
=10×14+292.5
=140+292.5
=432.5
4.5×65参照尾同首合十的口算方法.

热心网友 时间：2024-10-24 23:42

2.5×56+4.5×65
=2.5×8×7+（4+0.5）×65
=20×7+260+32.5
=140+260+32.5
=432.5

热心网友 时间：2024-10-24 23:43

2.5×56+4.5×65
＝0.5×（5×56）＋0.5×（9×65）
＝0.5×280＋0.5×585
＝0.5×（280＋585）
＝0.5×865
＝432.5

热心网友 时间：2024-10-24 23:43

(2.5+4.5)×56×65