一个可供小学数学运算的程序，要求能计算0——100正数加减乘除四则运算，如结果为小数四舍五入保留小数点后两位，根据输入题数出题，题目应为随机，每次应不一样。-An alternative elementary school math program requirements can calculate the positive number of 0- 100 Math four operations, such as results decimal rounded to two decimal