考点:小数四则混合运算
专题:运算顺序及法则
分析:(1)(3)根据加法交换律简算即可;
(2)(8)从左向右依次计算即可;
(4)根据乘法分配律简算即可;
(5)首先计算二级运算,然后计算一级运算即可;
(6)首先计算乘法,然后根据减法的性质计算即可;
(7)根据乘法交换律和结合律计算即可;
(9)首先计算小括号里面的,然后根据减法的性质计算即可.
解答:
解:(1)9.9+1.2-9.9+1.5
=9.9-9.9+1.5+1.2
=0+1.5+1.2
=2.7
(2)10-3.45+2.55
=6.55+2.55
=9.1
(3)5.58+2.74-1.58
=5.58-1.58+2.74
=4+2.74
=6.74
(4)1.5×10.2
=1.5×10+1.5×0.2
=15+0.3
=15.3
(5)3.8+3.22÷23×13
=3.8+0.14×13
=3.8+1.82
=5.62
(6)10×2.3-(3-2.03)
=23-3+2.03
=20+2.03
=22.03
(7)1.25×3.6×8
=1.25×8×3.6
=10×3.6
=36
(8)800+32×17
=800+544
=1344
(9)12.3-(8.37-4.88)-4.51
=12.3-3.49-4.51
=12.3-(3.49+4.51)
=12.3-8
=4.3
点评:此题主要考查了小数、整数四则混合运算,注意运算顺序,注意加法、乘法运算定律和减法的性质的应用.