题目内容
10.怎样简便怎样计算.58×58+58×42 | 3874-(874+1500) | 347-129-147 |
6000÷125÷8 | 25×125×32 | 25×44 |
981+981×50+49×981 | (755+693)-(255+193) | 870×65+350×87 |
分析 (1)运用乘法的分配律进行简算;
(2)先去小括号,再算进行计算;
(3)运用减法的性质进行简算;
(4)运用除法的性质进行简算;
(5)把32化成8×4,再运用乘法的交换律、结合律进行简算;
(6)把44化成4×11,再进行简算;
(7)运用乘法的分配律进行简算;
(8)先去小括号,再运用减法的性质简算;
(9)运用乘法的分配律进行简算.
解答 解:(1)58×58+58×42
=58×(58+42)
=58×100
=5800;
(2)3874-(874+1500)
=3874-874-1500
=3000-1500
=1500;
(3)347-129-147
=347-147-129
=200-129
=71;
(4)6000÷125÷8
=6000÷(125×8)
=6000÷1000
=6;
(5)25×125×32
=25×125×8×4
=(25×4)×(125×8)
=100×1000
=100000;
(6)25×44
=25×4×11
=100×11
=1100;
(7)981+981×50+49×981
=(1+50+49)×981
=100×981
=981;
(8)(755+693)-(255+193)
=755+693-255-193
=755-255+693-193
=(755-255)+(693-193)
=500+500
=1000;
(9)870×65+350×87
=87×650+350×87
=87×(650+350)
=87×1000
=87000.
点评 整数混合运算的关键是抓住运算顺序,正确按运算顺序计算,适当利用运算定律简算.
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