Checklist
Keep a proportion's value separate from its display
The symbol can disappear while the factor of a hundred remains.
When it fits
- Percentages move between spreadsheets, forms, APIs or reports.
When to avoid it
- Do not infer the convention from one unusually small or large value; confirm the field definition.
Checklist
- The stored numeric convention is documented.
- Formatting is not mistaken for a conversion of the underlying value.
- A known example survives export and re-import without a hundredfold change.
Why it matters
Establish whether the field stores a decimal proportion or a percentage number. A value of 0.25 can represent 25%, while another interface may expect the number 25. Record the convention and test a familiar value before moving a whole column.
An example
A field expecting a fraction should receive 0.07 for seven percent, not 7.
Check your result
The same proportion is preserved across each boundary, independently of how it is displayed.
Keep this limit in mind
- Do not infer the convention from one unusually small or large value; confirm the field definition.
Connected ideas
Useful withAsk what the percentage is a percentage of
Evidence and sources
Supports
A decimal proportion and its percentage representation differ by a factor of 100 in their written numerical form.
A file format may store or display either convention; the actual field definition must be checked.
Prealgebra 2e, 6.1: Understand Percent · Conversions between percents and decimals