Most math formulas involve some Greek letters or perhaps some strange symbols like or perhaps a letter with a bar over the top. Thus in your example you have n observations each one of them is. This often works well.
The simplest way to find a formula is to click on a cell and look at the formula bar.
Type H2 into the Reactants box and hit Enter on your keyboard. Each element is represented by its atomic symbol in the Periodic Table eg. Dates times phone numbers and other multiple data records are often entered in. You can also switch to formula view which will display all of the formulas in the spreadsheet.