1
计算
0.75×20=
0.75×200=
0.75×0.2=
7.5×0.2=
0.75÷0.25=
0.125×8=
4.8÷0.3=
0.56÷28=
0.36÷0.4=
0.7×0.09=
3.6×0.3=
1.64+4.1=
10÷20=
24÷0.06=
8.65×10=
0.35×0.6=
30.8×0.1=
0.4×0.5=
9.6÷0.8=
0.108÷2=
3.9÷0.13=
3.9÷1.3=
0.39÷13=
0.39÷1.3=
0.25×0.4=
1.6÷0.8=
1.25×0.8=
0÷1.7=
9.6÷8=
5×0.24=

解析：这些题目都是基础的数学运算，包括乘法和除法，主要考察的是对基础运算的掌握和运算的准确性。
答案：
$0.75 × 20 = 15$
$0.75 × 200 = 150$
$0.75 × 0.2 = 0.15$
$7.5 × 0.2 = 1.5$
$0.75 ÷ 0.25 = 3$
$0.125 × 8 = 1$
$4.8 ÷ 0.3 = 16$
$0.56 ÷ 28 = 0.02$
$0.36 ÷ 0.4 = 0.9$
$0.7 × 0.09 = 0.063$
$3.6 × 0.3 = 1.08$
$1.64 + 4.1 = 5.74$
$10 ÷ 20 = 0.5$
$24 ÷ 0.06 = 400$
$8.65 × 10 = 86.5$
$0.35 × 0.6 = 0.21$
$30.8 × 0.1 = 3.08$
$0.4 × 0.5 = 0.2$
$9.6 ÷ 0.8 = 12$
$0.108 ÷ 2 = 0.054$
$3.9 ÷ 0.13 = 30$
$3.9 ÷ 1.3 = 3$
$0.39 ÷ 13 = 0.03$
$0.39 ÷ 1.3 = 0.3$
$0.25 × 0.4 = 0.1$
$1.6 ÷ 0.8 = 2$
$1.25 × 0.8 = 1$
$0 ÷ 1.7 = 0$
$9.6 ÷ 8 = 1.2$
$5 × 0.24 = 1.2$

圈出得数等于8的算式

解析：本题考查小数的乘除法以及加减法的运算。
$0.2×0.4 = 0.08$；
$1.5 + 6.5 = 8$；
$0.56÷0.7 = 0.8$；
$0.8×11 = 8.8$；
$0.01×8 = 0.08$；
$1.6×5 = 8$；
$0.64÷0.8 = 0.8$；
$3.2÷0.4 = 8$；
$0.5×40 = 20$；
$0.2×4 = 0.8$；
$8×2.5 = 20$；
$10.9 - 2.9 = 8$；
$3.2×30 = 96$；
$0.2×40 = 8$。
答案为：圈出$1.5 + 6.5$；$1.6×5$；$3.2÷0.4$；$10.9 - 2.9$；$0.2×40$。