题目内容
下面各题怎样简便就怎样算.
| 25×7×4 | 32+26+74+168 | 63×25+25×37 |
| 99×32+32 | 25×44 | 48×213-13×48. |
分析:(1)运用乘法交换律简算;
(2)运用加法交换律和结合律简算;
(3)(4)(6)运用乘法分配律简算;
(5)先把44分解成4×11,再运用乘法结合律简算.
(2)运用加法交换律和结合律简算;
(3)(4)(6)运用乘法分配律简算;
(5)先把44分解成4×11,再运用乘法结合律简算.
解答:解:(1)25×7×4,
=25×4×7,
=100×7,
=700;
(2)32+26+74+168,
=(32+168)+(26+74),
=200+100,
=300;
(3)63×25+25×37,
=25×(63+37),
=25×100,
=2500;
(4)99×32+32,
=(99+1)×32,
=100×32,
=3200;
(5)25×44,
=25×4×11,
=100×11,
=1100;
(6)48×213-13×48,
=48×(213-13),
=48×200,
=9600.
=25×4×7,
=100×7,
=700;
(2)32+26+74+168,
=(32+168)+(26+74),
=200+100,
=300;
(3)63×25+25×37,
=25×(63+37),
=25×100,
=2500;
(4)99×32+32,
=(99+1)×32,
=100×32,
=3200;
(5)25×44,
=25×4×11,
=100×11,
=1100;
(6)48×213-13×48,
=48×(213-13),
=48×200,
=9600.
点评:本题考查了四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律进行简便计算.
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(1) |
(2) |
一个数除以
2,等于这个数乘________.|
(3) |
(4) |
一个数除以
4,等于这个数乘________.|
(5) |
(6) |
一个数除以
5,等于这个数乘________.|
(7) |
(8) |
一个数除以
8,等于这个数乘________.(9)
下面各题怎么简便就怎么算:①
32.4×0.5=②
48×0.25=③
12.3÷5=④
7÷8=