These flashcards are effective for nurturing the right brain, even as children grow from infancy. Each month, 20 cards are flipped while listening to the CD's audio, and shown to the child. Children develop photographic memory, and through repetition, their right brain is trained. Within a week, they can recite the 20 cards without looking at them. The words they memorize are stored in the brain and are not easily forgotten. My son started attending Shichida Educational Institute at age 3, and my daughter at age 2. I feel they have a high vocabulary. (My son withdrew at age 7, and my daughter is still attending at age 6.) Flashcards are currently essential in the classroom and are considered important. Regardless of the volume or whether they are new or old, consistently using them trains the right brain. My son, who doesn't attend the classroom, still uses flashcards with his sister. Includes a progress check sheet. Shichida Educational Institute, normally costs around 27,000 yen. Cards 1-240, CD Single-sided printing with attached stickers.