On the campus of

# Puzzle

### Five Squares, One Square: Solution

In two previous blog posts I talked about a puzzle made up of five two by two squares, where each square was cut in two along a line from a vertex to the midpoint of a side. The challenge, which I gave in the first post, was to put the ten pieces together to form… Continue Reading

### The Relative Riddle

This week’s Puzzle Corner is a classic riddle requiring reasoning to reconcile. (Please forgive the crude alliteration.) While many of you have encountered this riddle before and already know the answer, the riddle probably caused curious consternation (I beg your pardon once more) the first time you saw it. Riddles like the one presented here… Continue Reading

### How Many Squares?

In this week’s puzzle students are asked to find out how many squares are in the figure shown. This is not a difficult puzzle, but it does require some careful observation, organization, and counting. I encourage you to turn to the puzzle right now and give it a try before reading on. This will help… Continue Reading

### The Bridge Crossing Challenge

This week’s puzzle is a brief study of network theory whose roots began with a problem that was first approached in 1735 in Köningsberg, Prussia (now Kalinigrad, Russia), In this puzzle, students attempt to draw routes that cross every bridge in a bridge puzzle once and only once. Click here to download the directions for… Continue Reading

### Flipping Fish

This puzzle has been around in various forms for a number of years. All forms begin with eight toothpicks or matches arranged in the shape of a fish. One version challenges you to move exactly three toothpicks to make the fish face the opposite direction. Another version challenges you to move just two toothpicks to… Continue Reading

### Arranging Rectangles

My thanks to Richard Thiessen for this week’s puzzle. It consists of six pieces that can be put together to make rectangular regions (the regions can be solid or have openings in their interiors). Please download the Vee Diagram: A Guide to Problem Solving article, for ideas about how to use this puzzle with your… Continue Reading

### Five Squares, One Square: Some Hints and an Extension

In an earlier blog post I proposed a puzzle made of five 2 by 2 squares, each of which had been cut along a line from a corner to the midpoint of an opposite side so as to form a right triangle and a trapezoid with two right angles. The challenge of the puzzle was… Continue Reading

### Alphabetical Puzzlers

This week’s Puzzle Corner is a collection of puzzles dealing with letters of the alphabet. While they are not necessarily mathematical in nature (although one could argue this point), these puzzles have a place in a well-rounded mathematics curriculum. Alphabetical Puzzlers is a collection of four puzzles that use letters of the alphabet in a… Continue Reading

### A-Point-ing Pennies

This week’s Puzzle Corner activity is a one-person game with a fascinating history that goes back thousands of years and spans three continents. Dominic Olivastro, in the book Ancient Puzzles, notes that archeologists found three curious etchings on the roof slabs of the ancient Egyptian temple at Kurna which date back to around 1400 BCE.… Continue Reading

### The Eight-Digit Puzzle

Using a piece of scratch paper, cut eight rectangular cards that will fit in the boxes below. Write a 1 on the first card, a 2 on the second card, and so on, until you have the cards numbered from 1 to 8. The challenge in this puzzle is to place the number cards in… Continue Reading