Cross-figures by Yochanan Dvir

Here are eighty excellent Cross-figure (also known as crossnumber or figure logic) puzzles by Yochanan Dvir.

Puzzles 1-20
Puzzles 21-40
Puzzles 41-60
Puzzles 61-80

Here's a little info about the puzzle constructor:

Yochanan Dvir

Born in the year 1923 in Warsaw (Poland), survivor of the Holocaust and Warsaw Ghetto, Yochanan Dvir has lived since 1946 in a small community in Israel.

A mechanical engineer by education, he published several technical books and lexicons.

"At the end of the last century, I received two books of Cross-figures. I liked them and began to construct such puzzles on my XT computer, mostly for myself to solve. When I had eighty puzzles saved, I printed them in pocket-book format and even sold three copies on Amazon.com.
Some years later I found that I enjoy children's literature, stories, folk and fairy tales (maybe a sign of senility?). My granddaughters were just in the book-reading stage, so I began to translate stories into Hebrew for them, from about seven or so foreign languages which I could read and understand.
In the year 2005, I began to publish the stories on my website www.sefer-li.net, (which means "my book") and today there are over 1,500 such stories, mostly illustrated, on my site, with several hundred visitors daily. All this I've built and managed myself from scratch."

Looking for more cross-figure puzzles? I highly recommend the book Crossnumber Puzzles by Rainer Typke, which you can buy on Amazon. This book contains 50 handmade puzzles of varying difficulty (most are quite difficult, in my opinion). Rainer's website crossnumber.com contains a number of these puzzles as well as an interesting tool to aid in constructing new ones, which is described in his book. Enjoy!

Neil Aggarwal's has provided some TripleCross puzzles, a hexagonal Cross-figure variant that has three axes. His website, 3DMathPuzzles.com contains other cross-figure-inspired puzzles. Neil's puzzles are very clever and fun (and extremely challenging) to solve. I highly recommend them!

Professor Emeritus William Sit has written a fascinating paper on cross-figure puzzles (On Crossnumber Puzzles and the Lucas-Bonaccio Farm). This paper includes a very challenging and interesting puzzle.