A young person receives a numerical result without explanation and uses it in a presentation. I propose to reconstruct data, operations and units of measurement.

In the hypothetical example, a percentage is applied to the wrong base. The problem is not solved by asking the system to be more certain.

We need independent control, proportionate to the consequence of the error. For educational exercises, the possibility of explaining the procedure matters at least as much as getting a seemingly plausible figure.

Background sources