Question

6.78×2.9+67.8×0.7怎么简便计算？

Answer 1

6.78×2.9+67.8×0.7
=6.78×2.9+6.78×7
=6.78×(2.9+7+0.1)-6.78×0.1
=6.78×10-0.678
=67.8-0.678
=67.122
所以，我们可以通过上面的简便计算过程，进行详细计算，得到答案67.122

Answer 2

6.78x2.9+67.8x0.7
=67.8×0.29+67.8×0.7（扩大缩小的性质）
=67.8x（0.29+0.7）（乖法分配律）
=67.8×0.99
=67.8×（1－0.01）（数的分解与组合）
=67.8－0.678
=67.122

Answer 3

6.78×2.9+67.8×0.7
=6.78×2.9+6.78×7
=6.78×(2.9+7)
=6.78×9.9
=6.78×(10−0.1)
=6.78×10−6.78×0.1
=67.8−0.678
=67.122

Answer 4

这是一道运用乘法分配律的变式题
6.78×2.9+67.8×0.7
=6.78×2.9+6.78×7
=(2.9+7)×6.78
=9.9×6.78
=(10-0.1)×6.78
=67.8-0.678
=67.122

Answer 5

可以这样计算的
=6.78*2.9+6.78*7
=6.78*（2.9+7）
=6.78*（10-0.1）
=67.8-0.678
=67.122