| 5.78-0.29+2.22 | 13.4-1.24-3.76 | 9.37-5.39+0.63-0.61 |
| 5.48-(1.9+1.48) | 3.42-2.75+6.75+6.57 | 15.3-8.75+5.75 |
分析 (1)利用加法交换律与结合律计算;
(2)、(6)利用减法性质计算;
(3)利用加法交换律、结合律与减法性质计算;
(4)先去掉括号再计算;
(5)先算6.75-2.75,再计算.
解答 解:(1)5.78-0.29+2.22
=(5.78+2.22)-0.29
=8-0.29
=7.71
(2)13.4-1.24-3.76
=13.4-(1.24+3.76)
=13.4-5
=8.4
(3)9.37-5.39+0.63-0.61
=(9.37+0.63)-(5.39+0.61)
=10-6
=4
(4)5.48-(1.9+1.48)
=5.48-1.48-1.9
=4-1.9
=2.1
(5)3.42-2.75+6.75+6.57
=6.75-2.75+3.42+6.57
=4+3.42+6.57
=7.42+6.57
=13.99
(6)15.3-8.75+5.75
=15.3-(8.75-5.75)
=15.3-3
=12.3
点评 考查学生对四则运算法则以及运算定律和运算性质的掌握情况.