Unit 9 Contents

Now play Factor 40 twice with your partner. The rules are the same, but the game board has numbers from 1 to 40.

11. How was playing Factor 40 different from playing Factor 20?
12. What new strategies did you learn playing Factor 40?

After playing a few games of Factor 20, Jerome noticed that sometimes when he chose a number to mark, his partner actually got more points than he did on that turn. That was because the sum of the factors was greater than the number he picked. For example, in their third game, Jerome marked 20 for his first move. Ming was then able to circle 1, 2, 4, 5, and 10. Jerome got only 20 points, while Ming scored 22 before he chose his own number. He realized that a good way to score more points than his partner was to pick large numbers with only a few small factors.

• 

13. What is the best first move Player X can make to start a game of Factor 20? With that move, how many more points does Player X get than Player O after the turn is over? Show how you found your answer.
14. What is the best first move Player X can make to start a game of Factor 40? How many more points does Player X get than Player O after the turn is over? Show how you found your answer.
15. If a game board had the numbers from 1 to 100 on it, what would be the best first move Player X could make? How many more points would Player X get than Player O after the first turn is over? Show how you found your answer.