1, we have learned the method of counting with a counter. Besides using a counter, there is also a convenient tool for counting and marking, that is, an abacus. Do you want to know abacus? What do you want to know about abacus? Know the names and positioning of the parts of the abacus.

2. What are the parts of the touched abacus? When you mark the number on the abacus, you should choose a file on the abacus as a mark. The first file is custom-made, and the second file is 10 digits and the third file is 100 digits. When all the beads are near the box, it means that the abacus has not been dialed. When marking the number, dial the bead against the beam, with a lower bead indicating 1, an upper bead indicating 5, and a gap indicating 0.

3. Pay attention to the characteristics of each number of 1 to 9, and explain the method of three-finger division of labor. When you dial 1, 2, 3, and 4, use the mother bead to lean against the beam. When you dial 5, it is generally not indicated by five lower beads, but by one upper bead. When you dial 6, 7, 8, 9, and 9 with your middle finger, dial the bead against the beam at the same time.