随机生成十以内加减法(含三个数的加减混合)

989-8 =19-8+8 =1备注Q列为0的是不“合法”的算式477-4 =37-4+3 =1822+8 =102+8-8 =1433+4 =73+4-9 =0288-2 =68-2+0 =1722