# Author Archives: Dave Youngs

### 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

### 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

### Time Marches On

This week’s Puzzle Corner activity is a simple problem with surprising results. The question posed in the puzzle is: “How many times during a day (24 hours) do the hour and minute hands of a clock point in the same direction?” The obvious answer seems to be 24, yet this is not correct. Students are… Continue Reading

### April Riddles

This week’s Puzzle Corner activity is a collection of riddles that are appropriate for the week that begins with April Fool’s Day. These riddles are the types of brainteasers loved by mathematicians and other people who enjoy mental challenges. Solving them will take logical reasoning, thinking outside the box, and persistence. These problem-solving skills are… Continue Reading