numbers question

how does one add a drop-down list of possible selections for a form

You mention "form." Are you using Numbers for iOS? That has forms. In the underlying table for the form just select cells with the values you want in the Pop-Up Menu and format as Pop-Up Menu. When you create a form based on that table the form will include the Pop-Up Menu.

Numbers for the Mac does not support form. But you can set up a Pop-Up Menu in cells the same way. Select cells containing the values you want in the menu and in the Cell tab of the inspector at the right choose Pop-Up Menu under Data Format.

SG

You can format the cell as a pop-up menu cell, then create the list of itms in the format inspector, but it's usually easier to follow the instructions below:

If you have an empty column, big enough to accommodate your full list of items (maximum 25), use that. Otherwise, add a new column to the existing table, or insert a new table and add enough rows to fit the full list of items for the menu.

Skip the header cell (if your table has a header row), and starting with the first non-header cell, enter your items, one to a row, in the order you want them to appear in the pop-up menu's list.

When you've entered the last item, proofread the list to check for spelling errors or typos.

When satisfied that all is OK, select all of the cells containing menu items, then click the Format brush to open the Inspector panel, and choose Cell.

Set the Data Format to Pop-up menu, then set Start with to either First item or Blank.

Each of the cells selected now contains the same pop-up menu, each set to display the item that was entered in that cell.

If you chose Start with Blank, choose any one of the cells and use the pop-up control attached to the cell to set it to 'none'.

If you chose Start with First item, choose the first cell in the list (which is already showing that item)

Copy the cell you selected, then paste it into the cell(s) where you want that menu to be placed in the spreadsheet.

The table or column or cells you were using to create the pop[up list may then be deleted.

Regards,

Barry