Age 11 to 16
Excel has two useful functions for work with fractions : LCM &
=LCM(number1, number2, . . . ) returns the lowest common multiple
of a set of integers, that is the smallest positive integer that is
a multiple of all integer arguments number1, number2, and so
The LCM gives the new denominator for adding or subtracting
fractions with different denominators.
=GCD(number1, number2, . . . ) returns the largest integer that is
a factor of all the integers.
GCD finds the common factor required to reduce a fraction to its
simplest form. 6/9 becomes 2/3 because 6 and 9 both contain a
factor of 3.
If these functions are not available, run the Setup program to
install Analysis ToolPak.
After you install the Analysis ToolPak, you must enable it by using
the Add-Ins command on the Tools menu.