Konno Hachimangu Shrine is located in Shibuya. This shrine is known as the shrine for sangaku. Sangaku refers to a votive tablet depicting a math puzzle given in devotion to a shrine or temple by a wasan (Japanese mathematics) mathematician.
In this shrine,you can see actual sangaku from the Edo era. Many students in Edo offered sangaku after completing difficult mathematics problems and vowed to study even harder afterwards.
Konno Hachimangu Shrine