Explained here:

https://tvtropes.org/pmwiki/pmwiki.php/UsefulNotes/OldBritishMoney#:~:text=The%20'stroke'%20or%20'slash,would%20be%20%223%2F%2D%22.

Think your chip would be read as "Two And A Half Shillings Exactly." No pence needed.

Frankly this bit about No Pants makes me embarrassed.