The McGraw Hill 6th grade book series of games.
Instructions:
Find three coins of different sizes (e.g. quarter, nickle, penny). Flip each and record the head/tail value. Look up the total with tip . Flip the three coins and do a look up in the total excluding the tip . Determine the percentage tip . Your opponent may challenge you. Look up the answer in the table on the next page. If you are right and your opponent didn't challenge you, you get a point. If you are right and your opponent did challenge you, you get two points. If you are wrong and your opponent challenged you, your opponent gets a point. If you are wrong and your opponent didn't challenge you, nobody gets a point. Your opponent plays next.
 vals[0] 
Tips
Coin tosses (largest to smallest): TTT TTH THT THH HTT HTH HHT HHH
Total with tip 117 119 121 123 125 127 129 131
Total without tip 97 99 101 103 105 107 109 111

On a different page so the players have to turn to it...