How should one write "one and two" in short form - 1&2 or 1 & 2? Are there any particular rules regarding this?
In context:
You may choose to do Information Technology Units [1&2/1 & 2] and then IT Apps Units [3&4/3 & 4] for VCE.
Chapters [1&2/1 & 2] of the book give the reader an idea of the protagonist's personality.
I had a look at this question and, whilst it had helpful and informative answers, it did not provide any detail on the usage of an ampersand to combine numerals.