Excel's VALUE function has only one argument: where a is the value stored as text that you want to convert into a number.
If you are interested in Excel’s text functions, you can also read the August 2023 Tech Q&A article “Join Text in Excel”, which explains the function TEXTJOIN, and the previous item in this month’s ...
If you've used data validation in Excel before, you probably selected the relevant cells, clicked "Data Validation" in the Data tab on the ribbon, and created the rule in the Data Validation dialog ...