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)(4)运用加法交换律与结合律简算;
(2)运用减法的性质简算;
(3)从左往右依次运算;
(5)(6)运用加法交换律与结合律以及减法的性质简算;
(7)先算括号内的,再算括号外的;
(8)把0.99看作1-0.01,运用减法的性质简算.
解答:
解:(1)36.87+19.38-0.87
=(36.87-0.87)+19.38
=36+19.38
=55.38
(2)68.15-6.47-4.53
=68.15-(6.47+4.53)
=68.15-11
=57.15
(3)6.36+4.43+0.749
=10.79+0.749
=11.539
(4)86.39-62.78+103.61-2.22
=(86.39+103.61)-(62.78+2.22)
=190-65
=125
(5)100.46-26.28-23.72-10.46
=(100.46-10.46)-(26.28+23.72)
=90-50
=40
(6)7.13-(5.13-0.6)
=(7.13-5.13)+0.6
=2+0.6
=2.6
(7)0.26+(52.04-46.89)
=0.26+5.15
=5.41
(8)13.86-0.99
=13.86-(1-0.01)
=13.86-1+0.01
=12.86+0.01
=12.87
点评:完成本题要注意分析式中数据,运用合适的简便方法计算.