1。 According to the query of China Mathematics Education Network, the root number indicates that the square of the whole root is equal to the number of roots, and the number of roots must be a number greater than or equal to 0, and the square of 1 can only be a number greater than or equal to 0, so the root number 1 is equal to 1. The root sign is a mathematical symbol, and the root sign is a symbol used to represent the root operation of a number or an algebraic expression.