By learning how to calculate with abacus, one can improve one's mental calculation which becomes faster and more accurate in doing large number calculations. Lotus Kalai Koodam provides the unique opportunity for students to learn Abacus‐based mental calculation (AMC) was derived from the abacus which means doing calculation, including addition, subtraction, multiplication, and division, in mind with an imagined abacus. We are providing 8 levels in Abacus. It is a high-level cognitive skill that run through calculations with an effective algorithm. People doing long-term AMC training show higher numerical memory capacity and have more effectively connected neural pathways. They are able to retrieve memory to deal with complex processes to calculate. The processing of AMC involves both the visuospatialand visuomotor processing which generate the visual abacus and perform the movement of the imaginary bead. Since the only thing needed to be remembered is the finial position of beads, it takes less memory and less computation time.