PrimePak - Factor Thinking Games

Master multiplication facts and divisibility rules while having fun playing card games with this unique deck of 171 cards. In all four games players form factor sets. Because 80 = 8 x 10, the numbers 80, 8, and 10 form a factor set. Factor sets can have more than three numbers. For example, the set 42, 3, 2 and 7 is also a factor set. Prime wild cards are used for prime numbers only.