- 08 Mar '08 19:25 / 2 editsI was just watching a local adoption of the show "Are you smarter than a 5thgrader?" and there was an old lady playing. She struggled to answer a question "Find a way to express 10 with five 9". While she figured out 99/ 9 - 9/9 = 10, I figured out 14 more ways to do it?

How many ways can you guys find?

P.s. I used derivatives, trigonometry, logarithms. There definitely are more ways, but the number I gave is how many I found during the question. - 08 Mar '08 19:47 / 1 edit

the old lady lost didn't she?*Originally posted by kbaumen***I was just watching a local adoption of the show "Are you smarter than a 5thgrader?" and there was an old lady playing. She struggled to answer a question "Find a way to express 10 with five 9". While she figured out (99 - 9) - 9/9 = 10, I figured out 14 more ways to do it?**

How many ways can you guys find?

P.s. I used derivatives, trigonometry, logarit ...[text shortened]... ere definitely are more ways, but the number I gave is how many I found during the question.

Because she found a way to express 89 inted of 10:

(99-9)-9/9=90-1=89 !!!

here's a easy one : 99/99 + 9 - 08 Mar '08 20:50some easy ones off the top of my head:

1. 9-9+9+(9/9)

2.(9/9)^99 + 9

3. 9-9+9+log(9-9)

4. 9-9+9+[log(base 9) of 9]

5. 9/9+[9th root of 9^9)

etc. if you allow the use of log base 9, 9th power and 9th root to achieve a value of 1, you can find tons and tons

i wonder how well 5 9s could be used to write the set of whole numbers, a la the classic four 4s problem? intriguing.. - 08 Mar '08 21:19 / 1 editI'll post some others I found:

sin9sin9 + cos9cos9 + 9 = 10

(99 - 9)/9 + derivative(9) = 10 (I suppose if you derive a constant function, hence a constant number, the derivative is 0)

(tg9ctg9 + 9) * 9 / 9 = 10

Eh, yeah, there really are tons of possibilities.

Ok, let's make 1 to 100 with five 9. (with only + - * /, hence no trigonometry, logarithmic expressions, calculus, combinatorics and other creepy stuff)

I'll start:

1 = (99 - 9) / 9 - 9