News and Observations from Wapella, Illinois: Home of the Wildcats.

Facebook Activity for Wapella

Thursday, December 6, 2007

Calculators Permitted: A Classic Quiz

Here is an old-timey arithmetic quiz.

How can four 9's make 100? You can subtract, multiply, divide, add to get the answer.

For example 9+9+9+9 = 36, and would be wrong. 9 x 9 + 9 + 9 is 99 and also wrong. Calculators are permitted, for those of you who did not know Mike Rabbe, Randy Vertichio, or Diane Benzek.

Here is another Niner, Forty Niner great Joe Montana, with his wife Jennifer.


Anonymous said...

(9/9) + 99

Come on JB.


Anonymous said...

Excellent work DIT! Did you receive any help from Jennifer Montana?


Anonymous said...

too easy, NEXT!!!!!!!! great work DIT!


Veeman said...

Now here's another brainteaser for you...prior to her marriage to the Golden Dome HOFer, what did Jennifer Montana do for a living, and how did she meet Joe?

Gaherty said...

You could also do this (if it is allowed)

(9X9+9)/.9 = 100

Anonymous said...

Gaherty--outstanding work as well. Both you and DIT have confined your solution to 4 nines. Tie goes to DIT, I think. May need a ruling on this.


gaherty said...

I get my smarts from the Wapella side

Anonymous said...

how about 9 divided by 9 plus 99 ?

Anonymous said...

does 99 count as one number or two? If it counts as two it and that is the only way to get the correct answer it is sort of a trick question.

A better example would use 99 in it.

Anonymous said...

Is 99 O.K.?

Anonymous said...


99 seems to be very close, and you did it with two nines. That seems better than four nines to me. However, if I'm not mistaken, there is an error, since 100=99+1. So, if the moderator is willing to tolerate an error of 1, there is a solution in only two nines. Many industries are very, very happy to have a 1% error, so congrats to you on this achievement.


Moderator said...


Your multiple math classes aside, I think the point is, does 99 count as two 9's, or as a single number 99.

I am all for 4 9's, in Lewis Carrol's question, as being sequenced in what manner the solver solves.

So, as 9, or 99, or 999, or 99.9 or what have you, good numbers all with simple operators between, the answers are fine. 99 itself is of course a wrong answer, but 99 as an operative number that leads to 100 is the track.

Great answers Wildcats, Redbirds, Maroon, and all!


Anonymous said...

Do you mean to tell me that the discussion under this headline has been almost exclusively limited to JB's silly little brainteaser? After 12 comments I see no dirty talk about the very beautiful Jennifer Montana. For fear that my post will be wiped off the map, I'll hold back my real thoughts. Nevertheless, I'd like to find a full body shot of her in a bikini and put it up next to my Farrah poster. Ira, I'm ashamed of you.


Anonymous said...

This is for Al.

Blog Archive