I.C.!
Chill-dren.
By iceicle!
Probably doesn't feel how he prefers it to...
They prefer radians.
Because they are not Cs.
The son answers, "Y." "Because I want to know!"
You take the letter "S" out of "sub", and the letter "F" out of "way".
Smiles. There is a mile between the first and the last letter.