Add a List of Numbers, and have it removed from the list after taken once and form is submitted.

What you're describing can be achieved using widgets. There are plenty to choose from so I'll just list them all below. These widgets track the number of submissions and automatically reduces the number of slots/options/items (or in your case, a list of numbers) for each submission. As soon as it reaches 0, the slots/options/items will be disabled and can't be selected by anyone anymore.

🔘 Appointment Slots Widget

🔘 Inventory Widget

🔘 Ticket Purchases Widget

🔘 Gift Registry Widget

🔘 Quantity Gift Registry Widget

Related guide: How-to-Add-a-Widget-to-your-Form