You must be an arithmetic teacher, I bet.
4 seconds sound clip from the The Day the Earth Stood Still (1954) classic radio play.
You can hear this line at 00:18:35 in the radio play.
Quote context
[...]
- Gee, just think... all the brains that goes on in here.
- What's all that stuff on the blackboard?
- It's a problem in celestial mechanics.
- He'll never get the answer that way. Let's see...
- Hey, it says, 'Don't erase, don't touch'!
- You must be an arithmetic teacher, I bet.
- 'Differentiate - the - equation.' There.
- Who are you? How dare you come in like this? How dare you write on that blackboard?
- Do you realize the professor's been working on that problem for weeks?
- He'll solve it in no time now.
- We came to see Professor Barnhardt.
[...]