Noughts and Crosses

[Harry_the_cat]

Everyone knows how to play noughts and crosses, right? Or Tic-tac-toe? But try playing to lose rather than win, ie try to force your opponent to get three in a row. It is quite challenging. You lose if you get three in a row.
In my teaching days, I would get my students to have a few games of noughts and crosses the normal way, and then change the rules to that above. I used to do this just before teaching how to anti-differentiate (obviously after they could differentiate), so they could get the idea of working in reverse and challenge their thinking. They loved it. Give it a go!

 

[firemath]

Me and my brother play tic-tac-toe occasionally, and have a perpetual state of stalemate.
We'll have to try this!

 

[Harry_the_cat]

Let me know how you get on!

 

[firemath]

Oh dear. I'll have to tell him he can't cross out my o's.

 

[firemath]

X | O | O
X | X | O
O | X | X

I win! This was our result.

 

[topsquark]

If you play X always start in the top left corner. The only way that O can stalemate is to play in the center first.

(I had some spare time in a Psych ward once. I also contributed three new verses for "The Itsy-Bitsy Spider." The spider didn't come out looking too good...)

-Dan

 

[Harry_the_cat]

... and they let you out??

 

[topsquark]

... and they let you out??

I cured three of the nurses. They got a bit worried about me after that.

-Dan