scss 数学运算，加减

/*加法*/$min-width: 200px;$max-width: 600px;.container {  width: $min-width+$max-width; // 800px;  margin: 0 auto;}/*减法*/.content{  width: $max-width - $min-width; // 400px  float: left;}/*乘法*/.border-box {  width: 10px * 2; //20px}/*除法-需要在外面添加一个小括号( )*/.border-box {  width: (100px/2)+ 100px; //150px}