Classes Command
 Classes( <List of Data>, <Start>, <Width of Classes> )

Gives a list of class boundaries. The first boundary (min) is equal to Start, the last boundary (max) will be at least the maximum of the List and the boundaries will be equally spaced between min and max.
Classes({0.1, 0.2, 0.4, 1.1}, 0, 1)
gives {0, 1, 2}
 Classes( <List of Data>, <Number of Classes> )

Gives a list of class boundaries. The first boundary (min) is equal to the minimum of the List, the last boundary (max) will be the maximum of the List and the boundaries will be equally spaced between min and max.
Classes({1, 3, 5, 7, 8, 9, 10}, 3)
gives {1, 4, 7, 10}
By convention this uses the a ≤ x < b rule for each class except for the last class which is a ≤ x ≤ b 