2023﹣55=
12.8+8.21=
1.4×5=
30×120=
×=
÷=
5﹣2=
×4÷×4=
523﹣23×7
4.97+6.38+5.03﹣4.38
60×()
×3.2+5.6×0.5+1.2×50%
()÷
9.4-3.2= 2×10%= + = 0.32= 3.14×8=
÷2= 8:13= 1- = × = 870÷29=
3.2÷0.01= 5.6+3.99= ÷ =
× = 4.1+1÷2=
3.57+1.43= 4.2× =
10-9.2= 0.6×0.6=
0.72÷0.8= 8× ÷8÷ =
第5幅有个棋子;第n幅有个棋子(用含有字母的算式表示)。