Would You Rather Math
This website offers a variety of math related would you rather questions. They are split into grade bands that go K-12. From what I can tell, you do not have to sign up to use these. There is an option to enter your email address and get popular Would You Rather questions, but you do not have to do that. I'm assuming they would send other emails as well as their "popular" options.
I envision these prompts being used as a bellringer or as a math talk, but I'm not a math teacher so you can choose how you implement them!
I will insert a picture of the website's recommendations as to how to use the prompts as well as steps on how to add the prompts to your own slides.