Matchstick puzzles
Teaching July 4th. 2008, 10:00pmI’m always trying to find new and exciting ways to keep kids interested in classes. This week in particular is challenging because the students have huge tests that count for half a year of work. The students that do come to class are not in the mood for more homework or anything intensive beyond blowing spit bubbles and drooling. I’ve stumbled upon “Matchstick puzzles” that seemed like a different sort of puzzle for students to try.
Since giving students access to fire making tools is a dangerous idea I would never, ever recommend, I settled on individually wrapped tooth picks. The local delivery restaurants drop these off from time to time with menu and phone numbers on them. I pick up a box and carry it with me from class to class. When I’m done giving homework and the students are milling about, I drop a series of puzzles on them.
All of the puzzles revolve around trying to make a particular shape in a limited number of moves. For example, you might need to change the shape of a particular object to match a criteria, but have a limited number of match sticks you can move to achieve it. This requires spacial skills, planning skills, and logic skills. Watching students work out the different paths to the solution is fun. However, one in three students are total dicks that would rather ruin the fun for everyone by destroying the design than actually try to use their brain to figure anything out.
Since they are easy to carry to each class, I bring a box with enough individually wrapped toothbicks for three to four puzzles. That way teams can work together, and any loser student that doesn’t want to try can be ditched from one of the groups and ignored without giving him the satisfaction of denying the entire class the solution.
Most of the students can repeat the simpler puzzles after I show them the solution. I usually give them about five minutes, drop a few hints about where to start, and see who finishes first. If it is looking like they won’t complete the puzzle in time, I’ll walk through the solution so that no one goes home before they see the answer. I always hated when I was left hanging on a puzzle without an answer.
7 Responses to “Matchstick puzzles”
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July 5th, 2008 at 4:23 pm
My favorite matchstick puzzle is the challenge to make four equilateral triangles out of six matches.
July 5th, 2008 at 8:28 pm
@1
LIAR! Making four triangles is impossible with six matches unless you rip them into multiple pieces or have crappy grammar.
However,making four triangle from six matchsticks isn’t as long as you intone the sentence correctly.
July 7th, 2008 at 6:16 pm
Liar? How dare you! It’s my favourite matchstick puzzle because it seems impossible. It’s actually not, you just have to be creative. And the creativity does not involve being creative with grammar or breaking the matches.
To assist: the length of each side of each of the four triangles is equal to the length of one match – and before you ask, the length of all matches are equal.
July 7th, 2008 at 8:15 pm
The answer to the four triangle puzzle, as I understand it, is the shape “4″ (made with three matches) and /_\, so 4/_\ = four triangle. Is this NOT the solution you were thinking of?
July 8th, 2008 at 3:44 pm
Surely you know me better than that…
July 8th, 2008 at 6:52 pm
Perhaps you could draw on your D&D experience to solve this one.
July 8th, 2008 at 9:48 pm
Ah ha. Make a four multi-sided die shape. That’s good. I’ll use that some time if I can.