Learn from other people"s mistakes

The proposed book contains mathematical texts containing a variety of errors: in the wording of allegations, in the conditions of tasks, answers and decisions. Many of them or their ideas "came" from real classes with schoolchildren, from various Olympiads and tournaments, from manuals addressed to students and teachers, but a number of texts were invented specifically. Most of these plots were previously used at various creative competitions of mathematics teachers (in their methodological part).
The book is addressed primarily to mathematics teachers, teachers of additional education, leading classes with schoolchildren, but it can also be interesting and useful for students in grades 7-11 and everyone who is interested in mathematics.
Compiled by: Blinkov A. D