How can I choose a number that when add to the global numbers, will not greater than number I have?

For example, I choose(1,5,10,25,50,100), When random is repeatedly added to world numbers, it has to be less or equal to 500.

You can do something like this:

drive.google.com/file/d/1EboS66gaAKHydr9o2v6VdLIFK99vhcEp/view

thanks!! I've got this covered now.