① - +
②1+1.9+2.9+3.9+4.9+5.9
③ - + -
④ -( + )-
⑤5- +
⑥2.8×0.5+5×2.72
9.5+4.2=
0.8×1.3=
14.1÷3=
3.5×2=
8.1-2.7=
1.4×0.3=
7.9+0.1=
2.5×4=
3x+4x=
5.69-1.7=
2.5÷0.5=
7.2-1.08=
5-3.2=
5.8+5.7=
3.5÷2÷5=
4÷0.8=
9+2.19=
6b-5b=
16.5-(6.5+2.7)=
10-6.2-1.8=
2.5×0.4=
0.7+0.35=
0.5×2.4=
3.64﹣1.04﹣0.6=
3.8+38=
1.25×1.4×4=
4+8+0.25=
1.8×2.8﹣1.8×1.8=
0.84÷0.07=
5﹣2.5=
+ = - = - = 7÷8+ =
+0.8= 12÷18= 1- - = - + =
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。