"Mathematical and Logical Works. Dodgson's considerable output of books and pamphlets of a
mathematical and, to a lesser degree, of a logical nature shows that he was both a conscientious
senior student of Christ Church and a mathematician of distinction. Prominent among these were
The Fifth Book of Euclid Treated Algebraically (1858 and 1868), A Syllabus of Plane Algebraical
Geometry (1860), An Elementary Treatise on Determinants (1867), and Euclid and His Modern
Rivals (1879). Of the last, his contemporary, the English author and librarian Falconer Madan,
wrote, "This is the most elaborate mathematical work produced by Dodgson and at the same time
a piece of literature." Apart from pamphlets and small textbooks for students, Dodgson's only
other important mathematical works were the two series of Curiosa Mathematica (1888 and
1802). Though he printed several logical puzzles, his only books in this area were intended for
children, though logicians consider Symbolic Logic (1896) important. Dodgson is also
remembered for his pamphlets and letters on "Proportional Representation," conveniently
collected and assessed by Duncan Black in The Theory of Committees and Elections (1958);
while Some Popular Fallacies about Vivisection (1875) is still quoted with approval.
 

     A woefully short biography of Dodgson as Mathematician
     A short bio of Carroll in German. There are also links to remarks on Alice, Looking-Glass,
     and A Treatise on Determinants. These are also in German.
     Algebra, computers, Boole and Carroll

Logic of Lewis Carroll

     What's logic?
     A solution to the Do cats eat rats? problem in the Netherlands.
     A logic puzzle with a Carroll influence.
     An interactive pillow problem. Insomnia gives one so much more time to create fun
     problems.
     The Schweinekotelett Problem well schweine is pig, so is this the pig cutlet problem? My
     German fails me.

Mathematics of Lewis Carroll

     Computer Science and Why Science, Language, and Literature by Matthew
     Belmonte. Chapter 2 of this book contains a few instances of 19th century abstract
     algebraic thought in Carroll's works.
     Divisibility by 11 Condensation of Determinants is mentioned in this conversation.
     Math problems inspired by Lewis Carroll, Ludwig Wittgenstein and le College de
     Pataphysique in French.
     A puzzling problem concerning wise men.
     A problem from the Snark.
     A subgroup of Mensa Espña dedicated to Carrollian mathematical recreations
     problems from Alice in Wonderland site provided by eminent Carrollian, Edward
     Wakeling.
     Sum of Squares problem.
     Right triangles of equal area problem.
     An interactive math teaching site

Games of Lewis Carroll

     Mathematical games and recreations with a mention of Dodgson Alice tangrams
     A mention of Carroll and tangrams
     More riddles.
     The game of Doublets with a few examples.
     An article in French on Doublets.
     Circular Billiards.
     Here's a program to create word ladders - that's Doublets for all you Carroll fans.
     Crossword puzzle with an Alice theme. Not by Carroll, but I thought it was of interest.