Solve It! Pip Seek
Edward S. Mooney · Mathematics Teaching in the Middle School · 2007
A domino is a rectangular tile. The dots, called pips, represent the two numbers on the tile. The domino pictured below shows the pair 1–5. A Double 6 set of dominoes consists of every possible pairing of numbers from 0 to 6 (i.e., 0–0, 1–0, 1–1, …, 6–6). Sets are also available in Double 9, Double 12, Double 15, and Double 18. How many pips are on a Double 9 set of dominoes?