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用简便方法计算.427-156-441230-299137+149+163.

题目详情
用简便方法计算.
427-156-44 1230-299 137+149+163.
▼优质解答
答案和解析
(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.