Have students work in groups of 2-4 people. I think the smaller the better. Make copies of the board (English) on white paper and make copies of the answers (Spanish) on different color papers. This way if they drop one on the floor, you know who it belongs to. Cut the answer key into squares and put pieces into envelopes or baggies. Hand each group a board and an envelope/baggie and have them place answers on top of the board. Example: my students would be mis. Keep a copy of the key not cut up to use as you walk around to quickly check their work. You could even do it as a race to create a little competition.