这个小软件是最近为一个朋友做的，比较适合刚上学了小孩学数学。默认密码是“123”。软件还有一些不如人意的地方，希望大家多提意见。-small software is a friend recently to do more for the kids just go to school studying math. The default password is "123." Some software is not satisfactory in the hope that we do so.