Perelman I. and . Interesting Arithmetic. Riddles and wonders in the world of numbers 9 ed. 1959 [djvu 194sc 192c . 8. 36mb]Book I. and . Perelman's "Entertaining Arithmetic" survived during the life of the author of seven editions and was revised and supplemented by him in the seventh edition, published in Leningrad in 1938. For the next 16 years, this book was not reprinted, and only in 1954 The State Publishing House of Children's Literature has released the eighth, abbreviated edition. In the present, the ninth edition underwent a significant revision of Chapters One, Two and Nine. These chapters are supplemented with new material: they are told in more detail about various systems of number, about how they were considered in the Chinese abacus, about the numerical giants of our reality ....... Newly told names of numeric giants .