The following problem just takes a little time. It doesn't require any math knowledge. Although, experience with problem solving strategies can help as always. Have fun, and don't give up ! :) It helps, if you print the prison plan and use a pencil. There is more than one solution. One Hundred Forty Five Doors A prisoner was thrown into a medieval dungeon with 145 doors. Nine, shown by black bars, are locked, but each one will open if before you reach it you pass through exac

I have been teaching this student from November, 2014. The family moved to NYC from upstate NY, and her mom was worried about her daughter's math knowledge. She told me in her first e-mail that: "The school was progressive and light on academics (no homework) and did not push too hard. She hates math (particularly division) and feels like she is behind in terms of strategies etc." After she reached out to me, we started to work with her child two times a week. After 8 month o

I just found this web page a few days ago. It seems useful in some cases, and I really like the Brain Teasers section. The problems are smart and make you think. Here is a nice problem from the web page I'd like to share. Enjoy ! The solution can be found here.