Texas Slim, the leader of the bandit gang, rubbed his hands together happily. He and his men had just robbed the Pecos bank. They had stolen twenty-one thousand dollars I "Okay, boys," grinned Slim,...
Number tricks
Ask a friend if she has a "lucky number." (It can be any number from 1 to 9.) Let's say her lucky number is 6. Tell her that you can show her how to get a whole row of sixes. Here's how: Have her...
Counting squares
Ahmose, chief builder for the king of Egypt, had a problem. He was building a new palace for the king and queen. The floor of the queen's bedroom was to be made of blocks of a special white stone...
Backward puzzles
> Most number puzzles ask questions, and you find the answers. Here is a > different kind of number puzzle. The answer is given, and so are the > numbers that were used to get it. After that, it's up...
The minus mystery
> Mildred Minuette wrote mystery stories. Her books were very popular. > In fact, they were so popular that her fans showed up at all hours of > the day and night, begging for autographs. Mildred was...
Magic squares
Have you ever seen a magic square? At one time, people gave all kinds of meanings to magic squares. But of course there is nothing really magic about them. They are just a special arrangement of...
Milo in Digitopolis
from The Phantom Tollbooth by Norton Juster "I hope we reach Digitopolis soon, said Milo. "I wonder how far it is." Up ahead, the road divided into three and, as if in reply to Milo's question, an...
Numbers everywhere
Think of all the numbers you use every day. At school, you go into a room that probably has a number on the door. Many times during the day, the teacher will tell you the number of a page to turn to...
What can you do with numbers?
A lot of surprising things I You can turn them into pieces and squares, And into irregular rings. You can split them into piles, You can give them funny names, You can make them into puzzles, You...
Counting machines
The abacus was the "great grandparent" of many other kinds of counting machines, such as the adding machine, the cash register, the computer, and the electronic calculator. It's easy to see where we...