Thank you for viewing! Please check my profile before considering a purchase! ★Product Description★ ・Provides an effective method for mastering 2-digit by 2-digit calculations in a short amount of time. ・Based on a method devised by current University of Tokyo students, and includes a wealth of practical practice problems. ・Aimed at elementary school students and above, and is suitable for all learners who want to improve their calculation skills. Especially effective for children who are not good at math! ★Please note that comments regarding purchase confirmation, product descriptions, images, or content already available in the profile will be ignored. Comments will be deleted after a certain period. ★If there is a problem with the product, please let me know before leaving a rating. We cannot provide support after the transaction is complete. ★To prevent trouble, please refrain from purchasing if you are looking for a perfect product or are overly sensitive. Thank you for your understanding. (^^)