Sometimes, when you enter a formula into Excel, your cell simply shows #####, instead of a meaningful value.
This problem is easily solved, by altering the cell width. The easiest way to do this is to drag the bar (shown in the above image on the right) until the cell is wider.
If Excel continues to display a string of # symbols, no matter how wide you make your column, it is likely that Excel is attempting to display the contents of the cell as a date or time, but the cell contains an invalid date or time value.
As dates and times are stored as positive numeric values within Excel, some values (for example negative values) are invalid as dates or times. Excel shows this by filling the cell with # symbols.
If the cell is not meant to contain a date or time, change the formatting of the cell.