To get a º symbol (you might need this when talking about alcohol proof)… on an iPhone/iPad, hold down the 0 [zero] and the degree symbol option comes up, in a similar way you can get é and other such things from the letters.
On a PC keyboard, the shortcut of holding down Alt and typing 0186 on the numeric keypad [then let go of Alt!] gives you the degree symbol. 0189 for ½. 0247 for ÷ (because a slash ain't obviously divide so this is handy). 0177 for plus minus ± because it looks so much better than: +/-. 0150 for a mid-sized dash –. 0151 for a long dash —.
Gosh I've led an exciting life!