If you have children one of these spiral apple corer/slicers is a must (for around $30 from specialty kitchen shops). It's another idea I have taken from our previous Montessori parent-toddler class. It was always a very popular activity.

Caspar has only just mastered it start to finish. However I have seen children half his age use one.  

Concentration and strength is required to turn that apple. 

Yum. Who could resist?