The official blog of Dr Mike's Math games for Kids

Cut A Bagel Into Two Linked Halves

For those of you who don’t know what a bagel is, it’s a bun with a hole in the middle. A doughnut made out of bread dough. If you can’t get hold of a bagel for the puzzle on this page, use a doughnut instead.

In my random web wanderings, I came across a page by George Hart called Mathematically Correct Breakfast. Don’t go there yet! If you do, you’ll spoil the puzzle….

Normally, when you cut a bagel, you get two ring-shaped pieces of bread. The pieces are not linked, so you can put them in a toaster, or pack them in two separate lunchboxes. George decided to solve this challenge :

Cut a bagel into two pieces that are linked like two links in a chain

His web page has detailed instructions on how to do it, including instructions on how to toast the linked bagel in a toaster oven. Importantly, if you like cream cheese, he also points out

“It is much more fun to put cream cheese on these bagels than on an ordinary bagel.”

and

“You get more cream cheese, because there is slightly more surface area.”

So, go and get a bagel or doughnut now, and see if you can solve the same challenge George solved. Then, pop over to George’s web page and see if you found the same solution as him. Then, challenge your friends, kids or students to do the same thing!