You can create a problem that combines a multiple choice and numerical input problems. Students not only select a response from options that you provide, but also provide more specific information, if necessary.
Currently, students can only enter numerals in the text field. Students cannot enter words or mathematical expressions, which might be confusing to students used to normal edX numerical inputs.
To create a multiple choice and numerical input problem:
<problem> The numerical value of pi, rounded to two decimal points, is 3.24. <choicetextresponse> <radiotextgroup> <choice correct="false">True.</choice> <choice correct="true">False. The correct value is <numtolerance_input answer="3.14"/>.</choice> </radiotextgroup> </choicetextresponse> </problem>