I was poking around in the Network tab at the various forks of this repo and spotted https://github.com/kjanat/mkdocs-exam by @kjanat

This has several new question types, the one I like best is:

Fill in the blank

Use three underscores (___) as placeholder in your question and provide the correct answer.

<exam>
type: fill
question: 2 + 2 = ___
answer-correct: 4
content:
<p>A simple addition problem.</p>
</exam>

Thinking of equivalent syntax in the new mkdocs-quiz syntax is not easy. The most literal translation would be:

<quiz>
2 + 2 =  ___
- [x] 4
</quiz>

However I think I prefer using placeholders instead of underscores. Need to be careful not to clash with Jinja / markdown syntax etc. Maybe double square brackets?

<quiz>
2 + 2 =  [[4]]
</quiz>

Could then try to be clever and even have multiple inputs, and markdown styling:

<quiz>
Fill in the well known idiom:

> _The quick brown [[fox]] jumped over the lazy [[dog]]_
</quiz>

Would generate something like this:

<!-- normal mkdocs-quiz framing -->
<quiz>
Fill in the well known idiom:

<blockquote>
  <em>
    The quick brown
    <input type="text" class="mkdocs-quiz-input" data-mkdocs-quiz-answer="fox" />
    jumped over the lazy
    <input type="text" class="mkdocs-quiz-input" data-mkdocs-quiz-answer="dog" />
  </em>
</blockquote>
<!-- normal mkdocs-quiz framing -->

With some CSS styling to make the <input> elements display inline and with nice styling.