Hi [VENUE COORDINATOR],

I wanted to write and confirm that the [NAME OF MTC] Math Teachers' Circle is meeting in [LOCATION] tomorrow night. We'll be arriving around [TIME], and I will pick up dinner on my way over. It would be great if you could provide plates, utensils, markers [AND ANY OTHER AGREED-UPON SUPPLIES].

We're expecting [#] teachers at the meeting tonight.

If you need to get in touch at any point, my cell phone number is xxx-xxx-xxxx.

See you tonight!

Best,
[NAME]