Syntax: RAND()
RAND() returns a uniformly distributed random number on the interval [0, 1). The number will change every time the sheet is recalculated.
Examples:
RAND() = 0.38952085, a number greater than or equal to 0 and less than 1
RAND() * 10 = 7.6609264, a number greater than or equal to 0 and less than 10
Excel function: RAND