Learning Resources tacklingAdd&Subtract Student Set. This fun card game is a great way to help children build confidence and fluency in mental addition and subtraction. This set has 84 colour-coded playing cards (42 purple and 42 yellow). Children will master number bonds and develop confidence and speed in tackling mental and written calculations. The Student Set has 1 set of 84 cards and is ideal for use in the classroom or at home. Measures 15cm W x 20cm L.