The first grade of primary school mathematics needs a computing rack. The counter of primary school students is a vertical five-speed counter, also called a five-speed computing rack. Generally, it consists of plastic counting beads, arched metal bars, plastic bases, baffles, digital sequence tables, etc. The corresponding bases in each column are labeled from right to left as 10, 100, 1000 and 1000 respectively. Mainly used in mathematics teaching for children and primary schools.