Thread: Four Nines
View Single Post
Old 2007-02-01, 19:47   #1
petrw1
1976 Toyota Corona years forever!
 
petrw1's Avatar
 
"Wayne"
Nov 2006
Saskatchewan, Canada

2×3×773 Posts
Default Four Nines

I don't know if this a new one for some of you OR as old as Mersenne himself and I hope I am not told again that it has been done. None of the links to other websites from the four-fours types of puzzle that I have seen yet have dealt with four-nines.

The Four 9's Puzzle: For you Disney fans this puzzle is also known as: "The 101 Damn Calculations". Using four 9's and standard mathematical operations formulate equations with the answer being each of the numbers from 0 to 100. All 101 (a prime number!!!) are possible.

Every calculation MUST use exactly four 9's and no other digits.
The allowable operations are:
· Addition: 9 + 9 = 18
· Subtraction: 9 – 9 = 0
· Multiplication: 9 * 9 = 81
· Division: 9 / 9 = 1
· Parenthesis: (9 + 9) / 9 = 2
· Square-root: √9 = 3
· Factorial: √(9!) = 6
· Exponential: √9^√9 = 27
· Concatenation: 99
· Decimal Point: .9 OR 9
. Some puzzles of this form allow the use of repeating decimals, my version does not required or allow it: I think using .9 repeating as 1 makes this puzzle too easy.
. Other versions allow the percent operator (i.e. √9% = .3). Again it is not necessary for this puzzle but if you have to use it.....
petrw1 is offline   Reply With Quote