Which term refers to the procedure to increase a variable's value by a fixed amount?

The term that refers to the procedure of increasing a variable's value by a fixed amount is "increment." Incrementing a variable typically means adding a specified value, which is often one, to the current value of that variable. This operation is frequently used in programming when you want to progress through a sequence, count occurrences, or adjust values in loops.

For example, in a loop that counts from 1 to 10, you might increment the counter variable by 1 in each iteration to move from one number to the next. The concept of incrementing is foundational in many algorithms and coding practices, making it a critical operation in programming.

The other terms provided represent different operations: decrement refers to reducing a variable's value; multiply involves scaling a variable's value by a factor; and assign relates to setting a variable to a specific value, rather than changing it incrementally.