I heave heard that Mac OSX Snow Leopard shipped with Numbers, an app used to manipulate spreadsheets. But I can't find it inside my default Mac OSX Mountain Lion installation. Checking with App Store, I found that this app is now cost $20 ($19.95). So Apple remove Numbers from default shipment of OSX and make it paid product?
All subsequent versions of OS X never bundled full versions of iWork applications, only iLife. So, neither OS X Lion nor OS X Mountain Lion bundle full iWork installations.
iWork could be bought through regular Apple stores or their online shop. The regular distribution – beginning with the introduction of the Mac App Store – is a digital download though.