杨秀慧 2010-3-1 19:10
四年级数学题
(56*57*34)/(38*21*17)如何巧算?
[tt7].
哇萨咪 2010-3-1 19:32
(56*57*34)/(38*21*17)
=(56/21)(57/38)(34/17)
=(8/3)(3/2)(2/1)
=8.
cleavergirl 2010-3-1 19:38
(56*57*34)/(38*21*17)
=56*57*34/38/3/7/17
=34/17*57/3*56/7/38
=2*19*8/38
=38/38*8
=8.