2009/2010×2009
=(2009×2009)/2010
=[(2010-1)×2009)]/2010
=(2010×2009-2009)/2010
=2009-2009/2010
=2008又1/2010
2009/2010×2009
=(2009×2009)/2010
=(2010×2009-2009)/2010
=2009-2009/2010
=2008又1/2010
2009/2010×2009
=2009/2010×(2010一1)
=2009/2010×2010一2009/2010
=2009一2009/2010
=2008又2010分之1
用简便方法计算:2009/2010×2009
2009/2010×2009
=(2009×2009)/2010
=(2010×2009-2009)/2010
=2009-2009/2010
=2008又1/2010。
回答:
2009/2010×2009
=2009/2010×(2010-1)
=2009/2010×2010-2009/2010×1
=2009-2009/2010
=2008又1/2010
运用了乘法分配律