Too many digits can distract from a useful difference and imply more certainty than the information supports. Too few can hide the change the reader is trying to understand.
Choose a display rule that fits the quantity and the purpose. Keep the underlying values available where exact detail matters, and explain any formatting that turns a value into a range or an abbreviated label.
Check totals and small values after rounding. Displayed parts may not add exactly to a displayed total, and a small positive value may appear as zero. A brief note can resolve that confusion without filling the page with unnecessary decimals.
- Match precision to the reader’s task.
- Keep exact values available when needed.
- Check the effect on totals and small values.
A small working example.
Imagine adding rounded values that no longer match the rounded total exactly. A short explanation can preserve the reader’s understanding of the difference.
A note to keep beside it.
Look for the comparison behind the visual impression. The baseline, time window, and group definition can change what a pattern seems to mean.
Follow a related question
Ask which situations the examples cover.
Examples shape the model’s taskDefine the start and end of the event.
Timing an ordinary eventKeep learning
Related background to continue exploring this subject.
NIST: statistical engineering W3C: accessibility, usability, and inclusion
