SassError: There is no module with the namespace "math"
Solution 1:
Figured it out. I needed to add
@use 'sass:math';
at the top of the file.
Solution 2:
What I could recommend you is an automatic (lazy) way - you may use:
$ npm install -g sass-migrator
$ sass-migrator division **/*.scss
From: https://sass-lang.com/documentation/breaking-changes/slash-div#automatic-migration