Kobon Triangles

Kobon Triangles

Kobon Triangles (Kobon Fujimura, 1981) Math Puzzles do not get more beautiful than this one from Japan.  It should be used by either elementary instructors who need to give their students practice holding a ruler and drawing a straight line or by junior high...
Venn Diagram Puzzles

Venn Diagram Puzzles

Venn diagrams are not taught well anywhere. With little effort, these diagrams can be brought to life with beauty and by going beyond that little 3 circle Venn diagram. At the very least a teacher should end a lesson on the three circle Venn diagram with a question:...