To sign machine, first open both hands and spread all fingers apart. Then bring your hands together by interlocking all fingers while keeping both thumbs sticking out, with palms open and facing your body at respective 45-degree angles. Finally, pivot your interlocked hands down and up a few times, as if to mimic the cogs of a machine.
Teach your advanced toddler the machine sign to introduce this concept which applies to many objects inside and outside the home: from toys and household appliances, to all kinds of transport vehicles.
This is a useful flash card taught best in conjunction with mechanical or battery-operated toys, household appliances, and transport vehicles.