用简便方法计算下列各题. 137+86+63 254+(524+146) 262-186-14 381-199 228+?

2025-08-24 07:55:55
推荐回答(1个)
回答1:

解题思路:根据加法交换律、加法结合律和加、减法的运算性质进行简算.
①137+86+63,
=(137+63)+86,
=200+86,
=286;

②254+(524+146),
=524+(254+146),
=524+400,
=924;

③262-186-14,
=262-(186+14),
=262-200,
=62;

④381-199,
=381-200+1,
=182;

⑤228+107,
=228+100+7,
=335;

⑥323-(223+65),
=323-223-65,
=35;

⑦178+297,
=178+300-3,
=475;

⑧168+249+132+451,
=(168+132)+(249+451),
=300+700,
=1000;

⑨694+238-594,
=694-594+238,
=100+238,
=338.
,4,用简便方法计算下列各题. 137+86+63 254+(524+146) 262-186-14 381-199 228+107 323-(223+65) 178+297 168+249+132+451 694+238-594.