Giants and Mermaids and Fairies! Oh My!

I have been following the hashtag #tmwyk and browsing Christopher Danielson's amazing blog and website Talking Math With Your Kids. It's got me looking for opportunities to talk math with my own 6 year old and 3 year old daughters.

At dinner a few nights ago, my oldest daughter offers this bit of wisdom:

S (6 years old):  Daddy, if there was a giant here, his little finger would be as big as you. 

Me:  Wow, that's big! How big do you think his foot would be? 

S:  As big as the table! 

Me:  Can I ask you another question? 

S:  (with big wide eyes in anticipation... or suspicion) OK.

Me:  If there was a fairy here, how big would her little finger be? 

S:  (after some thought) As big as my finger nail. 

L (3 years old):  Ask me one, Daddy! 

Me:  OK, How long is a mermaid's tale? 

L:  (thinking, thinking... grabs a fork) This long! 

At this point I'm a little confused. L loves mermaids and has a good idea what they look like and how big they are. I'm not sure why she has chosen a small fork to represent her tail.

Then some magic happens! She pulls her milk cup over and explains:

L:  If this (cup) is the mermaid, then this (fork) would be her tail.

She has created her own scale model using her place setting. And S (never to be outdone) has her own frame of reference:

S:  If the mermaid was 6 years old, her tail would be as long as my legs.

I thought that was a good place to stop. I was wrong.

L (my wife, ___ years old):  How come I don't get a question? 

Me:  If there was a dragon...