### Measures of Center: Mean

In this lesson, students get to learn about measures of center, or measures of central tendency. A measure of central tendency is a single number that other numbers are centered around. Itâ€™s a way to characterize a whole data set by using only one number.

The measure of central tendency introduced in this lesson is the mean. The mean is often referred to as the average. To calculate the mean, you add all the numbers in the data set, then divide by the number of data points in the set.

The mean is illustrated by converting a histogram of data points into an array. When this is done, the basis for the calculation formula is made evident.

### Measures of Center: Median

In this lesson, a second measure of center is introduced, the median. To find the median, you first put all the data points in numerical number. When there is an odd number of data points, the median is the data point that lies halfway between the ends of the distribution, which is in the middle of the sequence. If there is an even number of data points, the median is the average (mean) of the two data points in the middle.

### Measures of Center: Mode

In this lesson, a third measure of center is the mode. The mode is the number representing the data point that occurs most often.