The specific calculation process is as follows:

22+20

=(20+2)+20

=40+2

=42

The nature of addition calculation:

When two or more disjoint sets are merged into one set, the number of objects in the set is the sum of the number of objects in the original set. This explanation is easy to imagine. It is also suitable for advanced mathematics.

In addition calculation, two numbers with the same sign are added, the same sign as the addend is taken, and the absolute values are added. When two numbers with different signs are added, take the sign of the addend with the largest absolute value, subtract the number with the smaller absolute value from the number with the larger absolute value, and add 0 to any number to still get the original number.