The Signed Numbers set is a simple visual introduction to positive and negative numbers. The set includes two compartmentalized boxes containing number cards from zero to nine, as well as a few blank cards for writing on. The positive numbers are black-on-white coated card stock measuring 3 cm square, and the negative numbers are black-on-grey. Each box contains ten each of the numbers one through nine, twelve zeroes and fifteen blanks. The boxes measure 20 cm x 15 cm.