Abacus is an educational program for children that allows you to learn about an ancient device such as a whiteboard. The application imitates Chinese scores, which are divided in two frames with knuckles strung on the spokes. One half of the board is designed to count units and the other half is for fives. Abacus users can move the knuckles and the program will show the final numbers. It is also possible to work in the reverse mode, when the user enters a number, and the program itself moves the necessary kernels.