**PURPOSE: **To illustrate exponential increase from 1 through 2**64.

**DESCRIPTION: **The transparent chessboard serves as the starting point for the progression. Rice can be put on the chessboard for 1 through 2**5 (32) grains. Use beakers for 2**6 through 2**17 grains. (Note: 1 ml = 64 grains, approximately.) The
approximate volume of rice for successive powers of two are:

- 2**18 - 2**20: small waste basket, to 5.6, 11, and 22 cm, respectively.
- 2**21 - 2**22: large waste basket to 31 and 62 cm, respectively.
- 2**23 - 2**27: area of 1mx2m lecture table to 6.5, 13, 25, 50, and 100 cm, respectively.
- 2**28 - 2**37: area of front of room to 1, 2, 4, .......512 cm, respectively.

The total amount of rice is 2**65 - 1, or 3.7x10**19 grains. This is approximately four crops at 100 bushels per acre, with the entire land area of earth (about 4x10**11 acres) planted with rice!

**SUGGESTIONS: **Tell them the story about the invention of chess.

**REFERENCES: ** (PIRA
unavailable.)

**EQUIPMENT: **Rice, labeled containers through 2**16, transparent chess board.

**SETUP TIME: **5 min.