arithmetical instruction

例句：

1. 1. The arithmetical operation of addition is straightforward.
   加法运算是直截了当的。
2. 2.The arithmetical approach to problem-solving can be very effective.
   解决问题的算术方法非常有效。
3. 3.In mathematics, the arithmetic progression is a sequence where each term increases by a constant amount.
   在数学中，等差数列是指每一项都按照一个常数增加的序列。