When you install Pages v5+, Numbers v3+, and Keynote v6+, their earlier versions, if only installed in /Applications, will be moved to /Applications/iWork ’09. If you had installed iWork previously, then these older applications would already be in the iWork subfolder created by that install process.
Do not assume that the increase in version numbers above provide you with more features and functionality than the prior iWork applications. The do not, and in fact, because they are 64-bit rewrites, it will take Apple considerable time to reinstate hordes of missing features or design flaws. Keep and use these older applications instead. Read the customer feedback for each of these in the App Store, and you will understand why.
In particular, Pages v5+ now uses an entirely new and incompatible document (.pages) format to earlier Pages documents, and will permanently damage these older documents due to missing features. It is just a mess.