问题
解答题
用简便方法计算.
|
答案
(1)427-156-44,
=427-(156+44),
=427-200,
=227;
(2)1230-299,
=1230-300+1,
=931;
(3)137+149+163,
=137+163+149,
=(137+163)+149,
=300+149,
=449.
用简便方法计算.
|
(1)427-156-44,
=427-(156+44),
=427-200,
=227;
(2)1230-299,
=1230-300+1,
=931;
(3)137+149+163,
=137+163+149,
=(137+163)+149,
=300+149,
=449.