Here’s a neat challenge for your students: Ask them to find a way to represent each of the positive integers from 1 through 12 using exactly three 9’s.
This puzzle is a variation of the Four 4’s puzzle: Write each of the positive integers using exactly four 4’s. Some sample answers include the following.
1 = (4+4)/(4+4)
2 = 4/4 + 4/4
3 = (4+4+4)/4
This clock can actually be found online for purchase at cafepress.
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Answers! I need answers
Hello Anonymous,
My students are hard at work on this problem, which has turned into a clock-making project due next Monday the 12th. I will be posting their solutions at that time.
Good luck until then.
- Mr. L