Here are two board games for your students to practice converting units of weight and mass. The first game has students converting ounces, pounds, and tons. The second has students converting grams and kilograms. Several answers for the second game are decimals (7 grams=0.007 kilograms). An optional student recording sheet is included along with answer keys for both games. Directions for play are printed on each game board. After the games are printed, supply students with game pieces and a die (or paper clip for the game w/spinner), and students are ready to play. I also give my students calculators to use. These games are great for use as a math center and as an activity for early finishers.