Prefix and root word activity for elementary students

I have been tutoring a fifth grader who does not like to read.  In his class they are working on prefixes, so I created this activity to try to make decoding and words a bit more fun.  I took four common prefixes and wrote them each on 1/2 of an index card with a colored border on three sides.  Then I wrote root words on full index cards.  His job was to figure out which prefixes work with each root and put a colored dot on that card to match the border.  Each week I can add more words and  pull words from what we are reading that week.  While he would still rather play games on his phone, the activity seems to be interesting to him!