Why do this
requires children to work in a systematic way to
find all possibilities.
How will you record what you're doing?
How will you make sure you find all the possibilities?
The problem could be simplified to just two elves, then three
elves, so that children become confident with a particular system
before there are too many possibilities. You could ask learners to
record each possibility on a separate piece of paper so that a
system can be imposed afterwards and gaps can be filled.