It is often useful to bin numbers, and then plot on a continuous axis, or generally use as a continuous (green) pill. This enables adding a reference line.
Tableau has a bin option built in, but only produces a discrete (blue) pill. One advantage of the built-in bin options is the Show Missing Values is enabled.
//if the number you want to bin is both positive and negative then use:
INT( [Number] / [Bin Size] ) * [Bin Size] - IF [Number] < 0 THEN [Bin Size] ELSE 0 END
//if the number you want to bin is only positive then use:
INT( [Number] / [Bin Size] ) * [Bin Size]
Number - The field that you would like to bin
Bin Size - The size of each bin