## Basic College Mathematics (9th Edition)

This year there were $226,900$ more of these surgeries preformed than six years ago.
This year there were 555,800 knee surgeries performed in the United States. The number of knee surgeries performed six years ago was 328,900. $555,800-328,900=226,900$ This year there were $226,900$ more of these surgeries preformed than six years ago.