+ = 1- = 1.25× = - =
0.9+99×0.9= 0÷ = 1÷ = -0.5=
0.6×101= 3.2×2.5×12.5=
: =6:x
0.19+0.1= 20×70%= 1﹣= 2.7×4×2.5=
7.53﹣0.03= += +×0= 0.99÷0.1=
88×5450 3204×83
238÷46 356÷735.6÷0.7
照如图方式继续摆,第20个图形要用根小木棒,摆第个图形要用126根小木棒。