有两个同样的长方形，长都是8厘米，宽都是4厘米，把它们拼成一个正方形，计算这个正方形的周长．把它拼成一个长方形，这个新的长方形的周长你会计算吗？请你帮助小白兔靠墙围一个篱笆，它要围一个长24米，宽16米的篱笆．你有几种方法，哪一种方法最好，说一说你的看法？
6÷0.4=
2.5×4=
17.8﹣7.8=
6.6+3.4= ．
3.5×0.4= 2.5×0.4= 2.3×0.2= 2.1÷0.3=
7.1×0.4= 4.5÷0.15= 1﹣0.07= 0.42÷0.7=
12.4÷4= 2.5+1.5= 5.9×0.2= 0.48÷0.8=
0.25×1.3×4= 20÷0.01= 9÷0.01= 5.5÷1.1=
4.79+15.81= 0.3÷0.03= 0.2×0.1= 3.6+6.4=
0.56÷0.28= 1.2×0.3= 6.7﹣5.6= 7.25÷0.5=
4.2÷0.21= 4.3×0= 0.15÷0.5= 3.5×4=
5.32﹣5.3= 1.25×3.4×8= 9.6÷3.2= 3.6+2.4=
4.3﹣2.7+5.7= 7.2﹣5.6= 1.8÷0.9= 8.2×0.5=
5.6÷0.4= 8.5÷5= 5.6×0.5= 9.8÷0.2=
3.56×0.2= 3.4+1.5+4.6= 3.4×0.04= 6.12+3.48=
6÷0.12= 7.6÷4= 3.4×0.5= 5.2﹣3.2﹣1.8=
6﹣3.8= 7.5÷3= 3.5+5.4= 3×2.5=
3.5+6.5= 7﹣6.23= 8÷0.4= 0.25×2.5=
7.5÷0.5= 0.89﹣0.48= 3.5×0.8= 5.9﹣（3.2+0.9）=
0.4×0.3= 2.5×0.6= 8.8×0.1= 1.3×0.2=
5.28+1.6= 10﹣1.7﹣2.3= 6.09×0= 100×0.7=
3.2+4.8= 6.3﹣0.94= 0.25×4= 5×1.2=
4.8÷0.6= 4.8÷24= 3.6﹣2.4= 6﹣4.6=
8﹣3.4= 6×0.21= 1.25×8= 0.8÷0.5=
25×0.3= 0.63﹣0.3= 2.5+7.5= 34×0.1=
7﹣0.99= 21÷0.7= 5×2.4= 3×1.03=
3.2÷4= 1.5÷30= 5.1÷3= 0.37÷0.37=
0.28÷14= 0.16÷4= 8×0.05= 4×0.125=
4÷8= 7.5﹣0.7= 9﹣0.9= 7÷2=
2.8÷0.7= 21﹣0.21= 5÷0.01= 2.8×0=
7÷0.07= 6.3÷0.5= 0.32÷0.8= 1÷0.25=
0.25×0.4= 30×2.3= 3.6÷1.2= 2.5+1.2=
3.5×0.2= 9÷0.45= 0.96÷0.16= 4.8﹣2.9=
0.5÷0.25= 7.6+2.4= 0.17×0.4= 8.2×0.01=
1.72﹣0.73= 0.46÷2= 1.9×0.8= 1.2×0.3=
1﹣0.92= 0.16×0.7= 0.56÷0.16= 8÷0.6=
42.4+7.6= 1.58+2.42= 23.5+76.5÷0.25= 7.8﹣5.6=
1.25×4= 34.6÷0.2×4= 0.24÷0.3= 7.8×0.5=
1÷0.2﹣1×0.2= 57÷5.7= 8.1﹣0.05= 0.2×0.5=