1, abdication is not enough, carry ten, advance one. Carry addition is a mathematical operation and addition. For example, in decimal system, if the number of digits on one digit adds up to ten, then write the number of digits added up on this digit and input the number on the tenth digit to the next digit.

2, a mathematical operation, an addition. When two numbers are added, every time the result of a certain bit is greater than or equal to 10, you need to count 1 to the next bit, which is the carry. When there is carry addition in the operation, it is called "carry addition".