How is the mental arithmetic class going?

There are no more than six children in the class. They have notebooks with tasks, and the teacher has a laptop and a stopwatch on the desk. There is a large soroban in the classroom.The lesson begins with a hand warm-up. Children should use both hands to draw round the pictures and color them or do kinesiological exercises at the same time, focusing on the left hand. Further, you need to do exercises in notebooks, helping to concentrate your attention. Then miracles happen! The teacher begins to dictate examples of three or more actions for subtraction and addition, and students, actively clicking the bones on their abacus, write down the answers in a notebook.