[bazokajoe_2k]

This may be different for you, but on my laptop it works exactly how it says. Without shift, you have - and =, and with shift you have _ and +. So, in order to shrink, it's Command -, to and to increase it's, if you want to think of it this way, Command Shift =. Same way how to get into Help isn't Command /, but Command Shift / (?). I don't have a number pad on my lappy so I can't vouch for those dedicated +/- buttons.