The card deck contains a set of durable, laminated cards.? They can be used with the Everyday Mathematics card deck activity books or the Everyday Mathematics Games kit.? The two-sided card deck is used throughout Everyday Mathematics.? On one side, the cards show a number deck with 4 cards for each of the numbers 0 through 10, and 1 card for numbers 11 through 20.? Numbers are printed in blue or black to easily represent positive and negative integers.? The reverse sides of number cards 1-10 show fractions represented in a variety of ways.