ARTHUR Season 10 Scavenger Hunt

As an inside-joke, every episode of Season 10 included the number 10 somewhere.

Happy Anniversary

 * Jane and David Read are celebrating their tenth anniversary
 * The Ten Spot Diner
 * The jukebox costs a dime (10 cents) to operate

Flaw and Order

 * A 10 is on the man hole cover

Arthur Changes Gears

 * On The Ghost of Bicycles Never Ridden's shirt

Unfinished

 * On the blimp.
 * On the floor where the blimp took off.
 * On the light lamp on the way to the place where the blimp took off.

Binky vs. Binky

 * Binky writes that he is 10 years old on the sign-up sheet

Operation D.W.

 * On Buster's transforming car/boat

Do You Speak George?

 * At the very end of the episode a streak in the dirt is the 1 and the marble arena is a 0.

Buster's Special Delivery

 * On the hat of the mailman buster speaks to.