baker's half dozen

a dime a dozen

So common as to be practically or almost worthless.

all over hell's half acre

All over the place; everywhere.

baker's dozen

Thirteen; a group of thirteen.

banker's dozen

Eleven.

cheaper by the dozen

Handled more efficiently as a group, rather than individually.

decimal dozen

Ten, a group of ten.

half a brain

A very basic or minimal level of intelligence.

half a head

Synonym of half a brain.