1. 直接写出得数。
4.3+5.2=
0.7÷0.1=
8.35×2=
1.01×10×0.01=
12.8÷4=
5.2a÷1.3=
0.9×2.5=
10÷0.1×0.3=
0.8×1.1c=
2.8×2=
2.56×4=
6.3÷0.09×20=
6a-3a=
2n+0.1n=
3.4b×0.5=
4.3x-2x÷2=
a-0.7a=
2.4x+1.6x=
2a×3a=
45y-12y+y=
8x÷2=
7.5y-1.8y=
4.2c÷3=
9a-(6a+3)=
1.6×0.2=
0.84÷0.4=
81.2÷100=
6.8×2-1.7=
m-0.81m=
15.2÷0.8=
3.03×0.3=
3.5÷2.5÷0.2=

1. 9.5 7 16.7 0.101 3.2 4a 2.25 30 0.88c 5.6 10.24 1400 3a 2.1n 1.7b 3.3x 0.3a 4x $6a^{2}$ 34y 4x 5.7y 1.4c 3a-3 0.32 2.1 0.812 11.9 0.19m 19 0.909 7

9.5；7；16.7；0.101；3.2；4a；2.25；30；0.88c；5.6；10.24；1400；3a；2.1n；1.7b；3.3x；0.3a；4x；$6a^{2}$；34y；4x；5.7y；1.4c；3a-3；0.32；2.1；0.812；11.9；0.19m；19；0.909；7

2. 计算下面各题,能简算的要简算。
7×12.5×0.8
1.46×3.5+3.5×4.54
(7.25+0.5×1.5)÷32
8.36×10.1
3.65×0.15+1.5×0.035
9.4÷[(0.7+1.6)÷0.23]

2. 70 21 0.25 84.436 0.6 0.94

7×12.5×0.8
=7×(12.5×0.8)
=7×10
=70
1.46×3.5+3.5×4.54
=3.5×(1.46+4.54)
=3.5×6
=21
(7.25+0.5×1.5)÷32
=(7.25+0.75)÷32
=8÷32
=0.25
8.36×10.1
=8.36×(10+0.1)
=8.36×10+8.36×0.1
=83.6+0.836
=84.436
3.65×0.15+1.5×0.035
=3.65×0.15+0.15×0.35
=0.15×(3.65+0.35)
=0.15×4
=0.6
9.4÷[(0.7+1.6)÷0.23]
=9.4÷[2.3÷0.23]
=9.4÷10
=0.94

规定a*b= (a+b)÷(a-b)×b,求7.2*5.6。

7.2×5.6=(7.2+5.6)÷(7.2-5.6)×5.6=44.8

7.2*5.6=(7.2+5.6)÷(7.2-5.6)×5.6=12.8÷1.6×5.6=8×5.6=44.8