# Clustering

Clustering is a method used for estimating a result when numbers appear to group, or cluster, around a common number.

Example

Juan bought decorations for a party. He spent $3.63 for balloons, $3.85 for party favors, and $4.55 for streamers. About how much did he spend for decorations?

$3.63, $3.85, and $4.55 cluster around $4.

4 + 4 + 4 = 12 (or 3 × 4 = 12)

Thus, Juan spent about $12 on decorations.

See also estimation strategies.