In brief
HTML output represents the result of a calculation or user action. It can associate a result with input controls, but does not add mathematical logic itself.
Useful to know
HTML output represents the result of a calculation or user action. It can associate a result with input controls, but does not add mathematical logic itself. [1]
In a calculator, provide calculation and updating separately. Check invalid and empty inputs and how results are announced rather than assuming the element alone completes the functionality.
Sources
For further detail and to check the information: