We decided to try the folder approach. I wrote the words on coin envelopes (I bought a bazillion of these for some reason ages ago at Staples...they seem to work). Then I glued them on the folders. I wrote the definitions on strips of index cards (highlighting the root). She simply slides the definition strip in the matching word envelope. After we go over the words initially, this becomes an independent activity.
She especially liked that the first two roots were ped and man/manu....so what did we do after completing the tests? We had a little manicure/pedicure day! Of course!! She chose her colors to match the rubber bands on her braces (there's a Christmas theme going on with her!). Thank goodness I have teenagers with crazy nail polish colors!