The distance formula between two points on a number line can be used to find the distance between points.

The distance AB =              (1)

Or

The distance AB =              (2)

From figure; the coordinates of A and B are 2 and 10 respectively.

First try the formula (1):

Substitute the coordinate values in the distance formula.

The distance AB =

                                    (Subtract )

The distance is a positive unit and can not be negative, so the absolute value considered.  The distance AB = 8 units.

Next, try the formula (2):

Substitute the coordinate values in the distance formula.

The distance AB =

                                  (Product of two same signs is positive)

                                       (Subtract: )

                                         (Absolute value of 7 is 7)

The distance AB = 8 units.

The measure AB is 8 units.