# Computing Constants

Variables that begin with the letter "K" in MINITAB are considered constant rather than column variables. Constants are used when you want to store only one number rather than a series of numbers. The syntax is this:

`MTB> LET constant= arithmetic expression`

Your arithmetic expression must yield only a one number, as opposed to a column of numbers, as the result. The following example put the sum of column 6 into the constant K1.

`MTB> LET K1= SUM(C6)`

The following functions result in a single number, and are often associated with constant calculations.

COUNT(column) -- gives the number of items
N(column) -- gives the number of non-missing values
NMISS(column) -- gives the number of missing values
SUM(column) -- gives the sum of the values in a column
MEAN(column) -- gives the mean of the values in a column
STDEV(column) -- gives the standard deviation of values in a column
MEDIAN(column) -- gives the median of the values in a column
MINIMUM(column) -- gives the minimum value in a column
MAXIMUM(column) -- gives the maximum value in a column
SSQ(column) -- gives the uncorrected sum of squares of a column