bagginsbill mentioned how you sometimes had to vary two numeric inputs to keep parts of a pattern in balance. Use math nodes. Math_function Add is where you can control the settings. The default inputs are 1 and 0, and you just change the 1 to whatever you wish. Put the output to the inputs you want to control, set the numerics on the inputs to whatever your starting point is, and away you go. The obvious demo is the Tile node. Vary the size without varying proportions. (This "duh!" moment was brought to you by Antonia T. Tiger. Gave a hoppy Christmas. While using math, don't drink and derive.)