How can I create a ratio for my form?

I am trying to create a ratio requirement on my form.  I need the schools that are registering to have a 1 Chaperone to every 10 Students ratio, and it is required.  Can you help me figure this out so that I have it set-up already for next year's registration.

Are you trying to automatically fill the number of chaperons based on the number of students entered? If yes, you can do this with conditional logic.

Guide for condition: https://www.jotform.com/help/268-How-to-Insert-Text-or-Calculation-into-a-Field-Using-Conditional-Logic.

You only need to set up the condition like this:

So, with this condition, when 10 or below is entered in the number of students, the Chaperon is automatically filled with value 1. 

I've cloned your form and added this method, check the form here https://form.jotform.com/92666636659980. Enter values below 11 and below 21. 

I am sorry that I sent the question twice.  I forgot that a co-worker of mine gets the response emails.  Thank you for your help and I will let you know if I need any more assistance.

So I have tried your formula and when I enter anything over 21, it shows no number in the Chaperone field.  I have schools that bring up to 200 students, so I would require them to bring 20 Chaperones. 

I only have two conditions in the form. Below 10 and below 20, so above 20 won't add anything in the chaperon field. That was just a sample. You can have a condition to fill the field if the value is greater than 20.