Three digits addition and subtraction with regrouping.

• 三位数的加减(进位和借位)

Three digits addition and subtraction with regrouping.的用法和样例：

例句

1. The number is correct to three decimal places.
   这个数目精确到小数点后三位数。
2. He can receive a salary of five digits per annum.
   他一年的薪金达到五位数。