# What is it called when a set of numbers are adjusted to sum to one?

For example: An initial set $[1, 3, 4, 7, 2]$ sums to 17. By dividing each element by the sum, the elements sum to 1: $[1/17, 3/17,...2/17]$ sums to 1.

What is it called when a set of numbers are adjusted to sum to one?

Perhaps you're thinking of a normalizing constant? In your example, the normalizing constant is $1/17$.