This app focuses on the ease of use of the abacus on the app, and aims to realize smooth and comfortable operability. In addition to being able to use the abacus widely on the horizontal screen, the size and position can be freely customized according to the device. The number of digits can be used up to 15 digits, and the color and sound of the beads can also be set. You can challenge the addition and subtraction, multiplication, division questions according to the level. You will experience the operation of the abacus with finger-handling that is close to real. ◆Twitter 　https://twitter.com/p4pLIabLM00qnqn ◆Instagram 　https://www.instagram.com/hirokuma.app/