Abstract
"Das Zahlenbuch (A Book of Number)" is a textbook of mathematics in primary school (1-4 grade), written by E. Ch. Wittmann and the others. Konstruction priciples of this book are follows. (1) Focus learning contents on basic ideas. (2) Stressing on active-discovery learning and social learning (3) Saving a means of learning and expressions (4) A productive exercise (5) A natural individualising The feathers of a learnig content are "basic of a thousand", "power of five", "pattern of number", "lightning calculation" and "exploration of number realm". The feather of a teaching method is a holistic approach. This is characterized by "vague whole → analysis → sophisticated whole", "connecting a learning content" and "a progressive schematising (mathematising)".
