You can insert a non-breaking hyphen from the Character Palette. It's in General Punctuation, with a unicode value of 2011.
There's no keyboard equivalent for it, but you could set up an auto-correct entry that inserts it. E.g., auto correct "+-" with "‑". Because of how auto-correct works, you have to type a space in order for it to kick in, then delete the space. Thus you'd type +-<space><delete>. Kind of ugly, but still probably easier than bringing up the character palette each time.
Alternatively, if you keep the character palette up a lot of the time, you can add the non-breaking hyphen to the Favorites section to more quickly find it each time.
You can insert a non-breaking hyphen from the Character Palette. It's in General Punctuation, with a unicode value of 2011.
There's no keyboard equivalent for it, but you could set up an auto-correct entry that inserts it. E.g., auto correct "+-" with "‑". Because of how auto-correct works, you have to type a space in order for it to kick in, then delete the space. Thus you'd type +-<space><delete>. Kind of ugly, but still probably easier than bringing up the character palette each time.
Alternatively, if you keep the character palette up a lot of the time, you can add the non-breaking hyphen to the Favorites section to more quickly find it each time.
I can't find a way to type a non-breaking hyphen. There is no mention of one in Help and I can't find a key combination that produces one. You may have to do as Peggy suggests and use an en dash.