问题
解答题
口算:
996-283-117=
436+685-336=
99999+9999+999+99+9=
25×11×125×32=
答案
(1)996-283-117,
=996-(283+117),
=996-400,
=596;
(2)436+685-336,
=436-336+685,
=100+685,
=785;
(3)99999+9999+999+99+9,
=(100000-1)+(10000-1)+(1000-1)+(100-1)+(10-1),
=111110-5,
=111105;
(4)25×11×125×32,
=(25×4)×(125×8)×11,
=100×1000×11,
=1100000.