PgUp / PgDn buttons - one pair or two ?

Standard keys:

The regular pair of PgUp / PgDn are conventionally found to the top right of the keyboard and should work as expected.

Additional keys:

If your keyboard has a 'numeric pad' area on the right it will likely have a second pair of PgUp / PgDn buttons present. These, unfortunately, won't work, even when using the Numlock key which would normally toggle their functions.

Online searches show this to be down to the fact that standard Chromebooks do not have a numeric keyboard area so these keys are not [at least for now] enabled in the CloudReady port of ChromeOS.