A number of non-letter characters are used in mathematical operations ( note this isn't exhaustive, and doesn't list uncommon mathematical operators):

- Addition:
`+`

'plus', 'plus sign'. See here. Note the different use from action code concatenation. - Subtraction:
`-`

'minus', 'minus sign' or 'hyphen'. Note this is discrete from the typographic en-dash '–' (⌥+-) and em-dash '—' (⌥+⇧+-). See here. - Multiplication:
`*`

'asterisk'. See here. Note that in note $Text the asterisk is also used for generating (export) 'quick lists'. - Division:
`/`

'forward slash' or 'solidus'. See here. Note the separate use in Tinderbox path values. - Equals:
`=`

'equals sign'. Note this is also used for assigning values in action code expressions. - Less than:
`<`

'less than', 'left angle bracket'. See here. - Less than or equal to:
`<=`

. See here. - Greater than:
`>`

'greater than', 'more than', 'right angle bracket'. See here. - Greater than or equal to:
`>=`

. See here. - Increment:
`+=`

. See here. - Decrement:
`-=`

. See here.

In addition there are logical operators using single or double characters: