Question

1.2乘6.8乘8用简便方法计算

Answer 1

【解答】
1.2×6.8×8
=1.2×8 ×6.8
=9.6×6.8
=9.6×(7-0.2)
=67.2-1.92
=65.28

【思路解析】
简便计算无外乎运用凑整法，通过加法交换律、结合律或乘法交换律、结合律，调整运算顺序或分项、裂项，实现简化运算的目的。

Answer 2

1.2×6.8×8
=1.2×8×6.8
=9.6×6.8
=（10-0.4）×（7-0.2）
=70 - 2 - 2.8 + 0.08
=70.08 - 4.8
=65.28

Answer 3

1.2*6.8*8
=12/10*68/10*8
=(12*68*8)/100
=(10+2)(10-2)*68/100
=(100-4)(70-2)/100
=(7000-200-280+8)/100
=(7000-200-300+28)/100 (更好算, 但多一步)
=6528/100 =65.28