题目内容
197+98= | 148-79= | 526-298= | 38+127+62= |
25×16= | 390÷5÷6= | 125×47×8= | 270÷54= |
分析:(1)(2)(3)根据凑整法简算;
(4)根据加法交换律简算;
(5)先把16分解成4×4,再运用乘法结合律简算;
(6)根据除法的性质简算;
(7)根据乘法交换律简算;
(8)根据商不变的规律计算.
(4)根据加法交换律简算;
(5)先把16分解成4×4,再运用乘法结合律简算;
(6)根据除法的性质简算;
(7)根据乘法交换律简算;
(8)根据商不变的规律计算.
解答:解:(1)197+98,
=197+100-2,
=297-2,
=295;
(2)148-79,
=148-80+1,
=68+1,
=69;
(3)526-298,
=526-300+2,
=226+2,
=228;
(4)38+127+62,
=38+162+127,
=200+127,
=327;
(5)25×16,
=25×(4×4),
=25×4×4,
=100×4,
=400;
(6)390÷5÷6,
=390÷(5×6),
=390÷30,
=13;
(7)125×47×8,
=125×8×47,
=1000×47,
=47000;
(8)270÷54,
=(270×2)÷54÷2,
=540÷54÷2,
=10÷2,
=5.
=197+100-2,
=297-2,
=295;
(2)148-79,
=148-80+1,
=68+1,
=69;
(3)526-298,
=526-300+2,
=226+2,
=228;
(4)38+127+62,
=38+162+127,
=200+127,
=327;
(5)25×16,
=25×(4×4),
=25×4×4,
=100×4,
=400;
(6)390÷5÷6,
=390÷(5×6),
=390÷30,
=13;
(7)125×47×8,
=125×8×47,
=1000×47,
=47000;
(8)270÷54,
=(270×2)÷54÷2,
=540÷54÷2,
=10÷2,
=5.
点评:完成本题要注意分析式中数据,运用合适的简便方法计算.
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