In Problems 2 &3 , we know the sum and one addend . So we use subtraction to get the other addend .
第（2）、（3）题是已知两个数的和与其中的一个加数，求另一个加数，用减法计算。
2
Thus, the augend and the addend must each be small enough to fit within one memory location.
由此可见，加数和被加数都应足够小，以便能够合适地装入一个存储单元。
3
During these steps, some digits are selected for specific roles (e. g., first addend) in the addition operation, while the others are held in working memory, but not used in the current operation.