有理数

例句：

1. 1. Arithmetic is the study of numbers and their operations.
   算术是研究数字及其运算的学科。
2. 2.The teacher explained the arithmetic problem to the students.
   老师向学生们解释了这个算术问题。
3. 3. In arithmetic, we use addition, subtraction, multiplication, and division.
   在算术中，我们使用加法、减法、乘法和除法。