When I saw this series from Ken de Courcy, I didn't know what to think. Books of mathematical tricks using pen and paper? But with the impulse purchase, I found out. Pentertain, the first book in the trilogy, has six tricks: the old "life force," a matrix trick, two entertaining ways to multiple two two-digit numbers, a telephone number trick that has a method that I'd previously seen for currency serial numbers, and a goofy mathematical oddity that
Devin Knight put out as a separate manuscript. The second book,
Son of Pentertain, has six more things, five of which I don't think are very good and a variation on the old
Martin Gardner tic-tac-toe gambit that folks like Richard Osterlind and
Johnny Thompson have used.
Mistress of Pentertain, the third and longest book, has 25 tricks and gags that are a real mixed bag with a lot of junk. I'd give Pentertain 3/5, Son of Pentertain 2/5, and Mistress of Pentertain 2.5 out of 5. There are things of interest amidst the dross, but be forewarned: de Courcy wrote these books in a different time--almost 50 years ago--so there is a lot of offensive and blue material. If you're going to use some of these things, you're going to have to rework the patter. Otherwise, you'll never pentertain--or entertain--in public again.