Answers to question based on selections from previous multiple choice- cascading select?

I'm trying to write a survey that will frequently use a question set with
the following format:

Question 1. Multiple choice
Question 2. Integer or decimal associated with selections from previous
question.

So, for example, a question might be:

  1. Which species have you hunted in the last 4 weeks? (Multiple choice)
  2. How many of each of these did you catch? (integer, with a place to put
    the number after each of the species selected in Question 1.)

I thought this might be done with cascading select, but since there is no
obvious grouping cascade to this- I don't think that is the right approach.

I'm aware that a work-around could be to ask a series of questions of 'how
many (species x) did you catch?', but that would require the data collector
to enter a series of zeros for all the species that haven't been caught- a
tedious and time-consuming task, that would take up a lot of space in the
survey because there are so many potential game species.

Any help would be hugely appreciated, thank you!

P.S- I am brand new to ODK, so I'm afraid I am not yet familiar with the
technicalities. I'm using Excel sheet to make my forms.

Thanks