从小兔家到小猴家有2条路可走，从小猴家去游乐园有3条路可走，从小兔家经过小猴家到游乐园，有几种走法？
口算．
3.5﹣1.7= 54÷100= 6.4+3.6=
0.4+0.12= 1.25+0.6= 3.8×10=
425÷10= 0.07×100= 10﹣2.5=
口算：
0.4×0.02= 3.2+6.8= 0.39÷1.3= 2.4×2.5=
1÷0.125= 1﹣0.25= 0.62÷0.1= 99×0.25=
1.2×0.4+0.4×1.3= 4×（1.5+0.25）=
估算下面各题．
4.03×1.98≈ 3.95×0.2≈ 8.1×10.01≈ 16.2÷1.9≈
59.8÷3.1≈ 10.32÷0.21≈ 99.9÷0.5≈ 70.2×3.02≈
估算．
3.75×2.8≈ 96.2÷0.26≈ 6.27÷1.9≈
口算．
450÷9×5= 3.7÷100= 1﹣0.09= 6+6÷6×0=
4.3×1000= 363+3.66= 35+24﹣12= 9.9﹣（7.9﹣1.8）=
0.35÷10= 0.38+1.2= 26+78÷13= 24×5÷24×5=