1.直接写得数。(6分)
7.5+4.5= 0.25×16= 0.8-0.44= 2.5×0.3=
4.5÷0.9= 8.5×10= 5.2÷0.2= 1.2×6=
7.9÷0.1= 0.6×0.4= 4.5÷3= 0.65÷0.1=

解析：
这些题目主要考查小数的加减法、乘法和除法的基本运算。
答案：
$7.5 + 4.5 = 12$
$0.25 × 16 = 4$
$0.8 - 0.44 = 0.36$
$2.5 × 0.3 = 0.75$
$4.5 ÷ 0.9 = 5$
$8.5 × 10 = 85$
$5.2 ÷ 0.2 = 26$
$1.2 × 6 = 7.2$
$7.9 ÷ 0.1 = 79$
$0.6 × 0.4 = 0.24$
$4.5 ÷ 3 = 1.5$
$0.65 ÷ 0.1 = 6.5$

2.笔算。(8分)
0.76×2.8 2.14÷1.3(结果精确到百分位)
8.16÷0.8 36.8÷15(结果精确到百分位)

0.76×2.8=2.128
2.14÷1.3≈1.65
8.16÷0.8=10.2
36.8÷15≈2.45

3.计算下面各题,能简算的要简算。(12分)
4.27÷0.7×1.5 4.9×10.1 36.7÷1.25÷8
4.8×12.5 3.2×2.5×12.5 3.6×8.3+0.83×64

4.27÷0.7×1.5
=6.1×1.5
=9.15
4.9×10.1
=4.9×(10+0.1)
=4.9×10+4.9×0.1
=49+0.49
=49.49
36.7÷1.25÷8
=36.7÷(1.25×8)
=36.7÷10
=3.67
4.8×12.5
=0.6×8×12.5
=0.6×(8×12.5)
=0.6×100
=60
3.2×2.5×12.5
=0.4×8×2.5×12.5
=(0.4×2.5)×(8×12.5)
=1×100
=100
3.6×8.3+0.83×64
=3.6×8.3+8.3×6.4
=8.3×(3.6+6.4)
=8.3×10
=83