题目内容
计算下面各题.(能简算的要简算) (1)24×
|
(2)87.5÷12.5÷8 | (3)(
| ||||||||||
(4)91+91×(
|
(5)2.2×101 | (6)14.6-3.625-6.375. |
分析:(1)利用乘法分配律计算简便;
(2)连除变成除以括号里这两个数的积,87.5÷12.5÷8=87.5÷(12.5×8);
(3)利用乘法分配律计算简便;
(4)利用乘法分配律计算简便;
(5)把101变成100+1,再利用乘法分配律计算简便;
(6)把14.6-3.625-6.375变成14.6-(3.625+6.375)计算简便.
(2)连除变成除以括号里这两个数的积,87.5÷12.5÷8=87.5÷(12.5×8);
(3)利用乘法分配律计算简便;
(4)利用乘法分配律计算简便;
(5)把101变成100+1,再利用乘法分配律计算简便;
(6)把14.6-3.625-6.375变成14.6-(3.625+6.375)计算简便.
解答:解:(1)24×
+76×
,
=
×(76+24),
=
×100,
=50;
(2)87.5÷12.5÷8,
=87.5÷(12.5×8),
=87.5÷100,
=0.875;
(3(
+
)÷
,
=
×8+
×8,
=7+6,
=13;
(4)91+91×(
-
),
=91+91×
-91×
,
=91+14-13,
=92;
(5)2.2×101,
=2.2×(100+1),
=2.2×100+2.2×1,
=220+2.2,
=222.2;
(6)14.6-3.625-6.375,
=14.6-(3.625+6.375),
=14.6-10,
=4.6.
1 |
2 |
1 |
2 |
=
1 |
2 |
=
1 |
2 |
=50;
(2)87.5÷12.5÷8,
=87.5÷(12.5×8),
=87.5÷100,
=0.875;
(3(
7 |
8 |
3 |
4 |
1 |
8 |
=
7 |
8 |
3 |
4 |
=7+6,
=13;
(4)91+91×(
2 |
13 |
1 |
7 |
=91+91×
2 |
13 |
1 |
7 |
=91+14-13,
=92;
(5)2.2×101,
=2.2×(100+1),
=2.2×100+2.2×1,
=220+2.2,
=222.2;
(6)14.6-3.625-6.375,
=14.6-(3.625+6.375),
=14.6-10,
=4.6.
点评:考查了运算定律与简便运算,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律简便计算.
练习册系列答案
相关题目