This conversion helps when checking rates, reading decimal shares in exported data, or rewriting a probability in percentage notation. It does not determine what the rate measures. A value of 0.08 might describe a share, an interest rate or a change; the surrounding calculation provides that meaning.
Be careful with spreadsheet formatting. A cell containing 0.085 may already display as 8.5% when percentage formatting is active. Converting that displayed number again would multiply the quantity twice.
Choosing a sensible number of decimal places
A report might show 0.123456 as 12.35% after rounding to two percentage decimal places. That is a presentation decision; the underlying share remains 0.123456. Keep the original figure in a spreadsheet cell used for later calculations and round only the displayed percentage. Otherwise a series of individually rounded shares may fail to add to exactly 100%.
Reading a result without changing its meaning
Converting 0.2 to 20% does not tell you that something increased by 20%. It only changes the notation for the same quantity. To describe a change, you still need to know what was measured, which starting amount was used and what interval the change covers. Include that context when you label the answer.