There are 53 cards in this set.Children will take a card. They will build the first number with unifix cubes and then add the next number of cubes to the first set of cubes. They should use 2 different colors to distinguish the 2 numbers. They will then count all of the cubes to get the sum and write the number in the box with a dry erase marker. Last the equation will be written. Magnetic numbers or number tiles can be put in the boxes instead of writing the number. This activity is great to use in Math Stations.