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