Logic Puzzles in Math

Math class is the first academic subject of the day, and in my class, we always try to start with a brain teaser of some kind. Some weeks, it’s a form of equation construction that the kids can each approach on their own level, such as ___ x ____ = 15. The two missing terms can be filled in with something as simple as 3×5 or something as complex as 1/4 x 60.

This week and last, we’ve been focusing on logic puzzles, with the whole class working together to solve them. Here is yesterday’s (taken from, with some rewording):

There are three doors in front of you. Behind one of the doors is a treasure chest; behind the other two are bottomless pits. The doors have signs; you know that the door leading to the treasure has a sign that is false and the other two doors have signs that are true. Here are the signs:

Door 1: The treasure is behind Door 2.

Door 2: The treasure is behind Door 3.

Door 3: The treasure is not behind this door.

Which door hides the treasure?

As they discuss this puzzle, the kids have been explaining their thinking very clearly, and each day they quickly arrive at the correct answer. As we work, we’ve also been carefully looking at the difference between considering logic (the clues and rules provided, what is excluded or allowed), and considering psychology (well, they never mention Door 1, which makes me think there’s something interesting about that door…).

This is great preparation for our computer coding unit, which will begin in January!

Renata McAdams

is our grade 3-4 classroom teacher. She has taught in a variety of public, charter, and independent schools, including a combined 3-5 classroom in Ann Arbor, Mich., for two years. Rentata graduated from Vassar College and received her M.S.Ed. from the University of Pennsylvania. She grew up in Oberlin, Ohio, and moved to Chicago from Philadelphia with her husband (then-fiancé) in August 2014.

In her free time, Renata enjoys singing, acting, dancing, and reading.