ISBN-13: 9780393003246 / Angielski / Miękka / 1965 / 260 str.
ISBN-13: 9780393003246 / Angielski / Miękka / 1965 / 260 str.
Professor Piaget discusses a set of investigations he and a team of co-workers carried out on the genesis of the notion of number in the child's mind.