考点:小数四则混合运算,运算定律与简便运算
专题:运算顺序及法则,运算定律及简算
分析:(1)根据连减的简便方法计算即可;
(2)根据加法交换律和结合律简便计算;
(3)变形为9.2-6.2-0.39计算即可;
(4)从左往右依次计算;
(5)先去括号,再从左往右计算;
(6)变形为(63.7-13.7)-(2.36+5.64)计算即可求解.
解答:
解:(1)10-3.57-5.43
=10-(3.57+5.43)
=10-9
=1;
(2)0.83+0.79+0.17+11.21
=(0.83+0.17)+(0.79+11.21)
=1+12
=13;
(3)9.2-0.39-6.2
=9.2-6.2-0.39
=3-0.39
=2.61;
(4)5.86-0.78+0.22
=5.08+0.22
=5.3;
(5)34.82-(3.82+15.2)
=34.82-3.82-15.2
=31-15.2
=15.8;
(6)63.7-2.36-13.7-5.64
=(63.7-13.7)-(2.36+5.64)
=50-8
=42.
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定律简便计算.