Error checking is an extremely intuitive function with looks for common errors that happen in formulas. These errors could include
- Formulas that result in an error
- Numbers formatted as text
- Formulas inconsistent with other formulas near them
- Formulas which miss out cells which are near others which have been included in the formula.
- Cells containing circular references
Any cells where the spreadsheet thinks there is an error are marked with a small green triangle in the top left corner of the cell.

In the following worksheet, cell G7 contains an error. This is evident from the appearance of the small green triangle.

If cell G7 is selected, an exclamation mark will appear together with a description of the error.
