Senior two students learn abacus with five beads, that is, one above and four below. Because the students are young, Wuzhu is more suitable for the students in the second grade of primary school. When understanding the abacus, first understand the structure of the abacus, that is, frame, beam and file. When counting, dial the ball against the beam, one upper ball means 5, one lower ball means 1, and the number is on the beam. Students count from the right.