I have a checkbox list of 6 choices. If someone ticks a choice I want a space to enter the amount they wish to choose. How can I do this?

eg The following is a checkbox selection question:

Type of art you will be submitting:

Painting

Ceramic 

Indoor sculpture

I want the ability once they have checked the type of art to allow them to enter the number they wish to submit (like a text box attached to the checkbox)

I see that there are 6 checkboxes that can be selected for the field Type of Art. Do you want to display only one Text box for entering the number? If so, I see that the Number field is already added to your JotForm. This field can be displayed only when any option from the checkbox field is selected by adding a condition to the form as shown below:

By adding this condition, the Number of pieces field is displayed only when any option from Type of Art is selected.

Hope this information helps! Let us know if you are referring to something different. We will be happy to assist.