"The stockings were hung by the chim..."
"What are stockings? Raph asked, interrupting Donnie at their reading lesion.

Splinter looked at the little five year old turtle, and sighed. "They are like socks." He explained. "Continue, Donatello."

"But wouldn't socks, I mean storkings, be better on feet?" Leo asked, before Don could start reading again, He looked rather confused. "Why are they hanging up?"
"Stockings." Donnie corrected, before Splinter had a chance to answer. "Not storking. Maybe they needed to be washed. And they are hanging up because the people who owned them are drying them?"

"Huh?" Mikey asked, scratching his head. "I thought this was about Christmas."

"The book has a picture, see? There are the socks near a fire, and fires are used to dry things. Right, Master Splinter?" He added, looking at their Master hopefully.

Splinter finally got a chance to explain what the stockings were for. He also made a mental note to observe Donatello's education more closely. That was very good logic for a five year old, he thought.