*Great Ideas of Mathematics Posters*: *Pythagorean Theorem* ($10.95), *Prime Numbers* ($10.95), *Infinity* ($10.95), *History of Pi* ($10.95) or the set of four for $36.95. Carolina Biological Supply Company, 2700 York Road, Burlington NC 27215, (800)334-5551, http://www.carolina.com/ .

This is a collection of four posters that give information about pi, prime numbers, infinity, and the Pythagorean Theorem. The posters can be bought singly or as a collection. Each poster comes with a booklet containing more information about the topic, problems for students and a bibliography.

When evaluating posters, I look at the appearance and the content. The consensus of my department about the appearance is that the colors are unattractive and that the posters are too busy. The four posters are done in muted colors of beige or orange. Each poster is 24" x 34" and contains a lot of information. It is very difficult to read anything on the poster without being a few inches away from the poster. Each poster could benefit from being divided into several slightly smaller posters, which were then enlarged.

In general the information is good and would be useful to someone who did not know much about the topics. The posters and the booklets contain a lot of information. In *Pythagorean Theorem*, the exercises are mostly about calculating Pythagorean triples. The *Prime Numbers* poster is copyrighted 1989, so the information about the largest prime number is dated. As of 11/14/01, the largest prime was 2^{13466917} -1 (more than 4000000 digits). The booklets could mention some appropriate internet sites such as: www.mersenne.org.

I would recommend these materials to someone who is looking for some basic information about prime numbers, pi, the Pythagorean Theorem or infinity.

Sylvia Lazarnick, Bellows Free Academy, St. Albans, VT