Accessing frontmatter from within a Templater template note

Thank you for explaining this, reaty. I understand it now. Thank you also for the alternative.

If I put

<%* let myVar = 10 %>

above the frontmatter

---
number: <%* tR += myVar %>
---

then the frontmatter is not recognised. If, however, I put it inside like this

---
number: <%* let myVar = 10 %><%* tR += myVar %>
---

then it all works.