To format cells containing a value to display as true/false, you can follow these steps:

1. Select the range of cells that you want to format.
2. Right-click on the selected cells and choose "Format Cells" from the context menu.
3. In the "Format Cells" dialog box, select the "Custom" category.
4. In the "Type" field, enter the following format code: ;;"TRUE";"FALSE"
5. Click "OK" to apply the formatting.

Now, the cells in the selected range will display "TRUE" or "FALSE" depending on their value. If the value is non-zero, it will be displayed as "TRUE", otherwise it will be displayed as "FALSE".

Alternatively, you can also use a formula to convert the values to boolean format. For example, if your values are in cells A1:A10, you can use the following formula in cell B1 and copy it down to cell B10:

This formula checks if the value in cell A1 is non-zero, and returns "TRUE" if it is, otherwise it returns "FALSE". You can then format the cells in column B as "TRUE/FALSE" using the steps above.