如何巧算81+691×9
问题描述：
如何巧算81+691×9
答
81+691×9
=9×9+691×9
=9×(9+691)
=9×700
=6300
如何巧算81+691×9
81+691×9
=9×9+691×9
=9×(9+691)
=9×700
=6300