If your intention is to always yield the same physical font size on any device then you are approaching mobile design naively, overlooking platform best-practices and possibly entering into legal complications due to failed Accessibility.
It is hard to determine what "too big" means to you. It might be more accurate for you to express that as "the screen is ...
If you can group your field logically, and distance groups from one another
You can place validation / number of digits input in the field so it is auto validated
You can signalize length of the number to be typed in, with the size of the field. One with 8 digits should be longest
Place fields one below each other. If you can sometimes group them, place ...
I recently designed some forms that share similar layout concerns with this. Here are some visual explorations you might consider:
If you really need the form to be shorter, you can sure play around reducing the heights of the input fields or the margins between them. I hope this helps.
Vertically below each other in an order that makes sense to your users.
The issue with putting fields horizontally next to each other is that they are sometimes missed.
Have a search for LukeW, he is a UX researcher at Google and has some amazing content on form best practices.
This is essentially the same as the answer above by @Mohammed Yaseen Ganai, but I felt that some more explanation was in order to really help you understand the suggestion.
The most important thing here is not breaking convention unnecessarily - there already exist UI elements to do exactly what you want to do: Radios and Checkboxes.
Switches are generally used when there are only one or two options. In this case, there a four options so checkboxes would work better. The options could be made more user-friendly and understandable with the addition of a verb:
Allow multiple valid answers [checkbox]
Allow multiple attempts [checkbox]
Shuffle questions [checkbox]
Shuffle answers [...
Standard behaviour for a switch is when the action takes effect instantly, a checkbox takes effect after a submit button is pressed.
I suggest you change the options you have for multiple attempts etc to checkboxes. Then move down the option for multiple answers to just above where you select the correct answer, here a switch makes sense. Group things that ...
Sections need to be distinguishable. Doesn't have to be by different background colour.
On my site, which is mainly and education site, I have a left menu with a distinct dark green background. The main content div has a consistent pale yellow. Photos are at least partially out of the main text stream, and are boxed, with italic captions. Users can ...