Numeric distance and rounding

Calculate a price’s distance from a benchmark and a fraction of that price. Separate nonnegative distance, fractional division and numeric rounding.

`ABS` removes a sign. `ROUND(value,places)` rounds a number; it does not promise fixed-width decimal display. Dividing by `3.0` preserves fractions.

Numeric distance and rounding: `ABS` removes a sign. `ROUND(value,places)` rounds a number; it does not promise fixed-width decimal display. Dividing by `3.0` preserves fractions.