3.6×= += ÷= 200×15%=
1÷0.2= :( )= -25%= 34÷17%=
3.5÷=
÷=
1÷0.25=
1÷=
0.3²×3.14=
+×7=
0.75:=
××2.7=
= 1.8-40%= 12÷=
×72%= 3.5×= -×=
×50%=
2- = 4.9× = ÷ = ×10=
× = 3.3× = ×12.5= 1÷ =
100×2.5%= 6.8÷10%= 1-35%= × ÷ × =
3.14×6= 2×3.14×12= + =
0÷20%= 60×30%= 25÷40%=
36× = ÷ = 3× ÷3× =
14÷=
18÷=
20÷=
72÷=
□□÷□=□□÷□=□□÷□
按照这样的方法继续摆下去,摆第5幅图需要 根小棒,摆第n幅图需要 根小棒。