Basic Arithmetic Operations

Equals

([{}]{})((){[()](<{}>)}{})

Not Equals

({}[{}](<()>)){{}{}(<(())>)}{}

Addition

({}{})

Subtraction

([{}]{})

Multiplication (Positive only)

({}<>)({<({}[()])><>({})<>}{}<><{}>)

(courtesy of Stack Exchange user MegaTom)

Multiplication

([({}<([({}(<()>))<>](<()>))<>>)<>]){({}[()]<(({})<({}{})>)>)<>}{}{}<>{}{}{}<>

(courtesy of Stack Exchange user Riley)

Integer Division (Positive only)

({}(<>))<>([()]{()<(({})){({}[()])<>}{}>}{}<><{}{}>)

Integer Division

(()()){({}[()]<([([({})](<()>))](<>())){({}())<>}{}<>{}{}<>(({})){{}{}<>(<(())>)}{}(({})<>)<>{(<{}([{}])>)}{}({}<>)<>({}<><({}<>)>)>)}{}({}(<>))<>([()]{()<(({})){({}[()])<>}{}>}{}<><{}{}>)<>(({}{}[(())])){{}{}(((<{}>)))}{}{}{(<{}<>([{}])><>)}{}<>

Modulo (Positive only)

({}(<>))<>{(({})){({}[()])<>}{}}{}<>([{}()]{})

(courtesy of Stack Exchange user feersum)

Absolute value

(([(({}))]<>)){({}())<>}{}{}<>{}

Factorial

({}<(())>){(({}<>)[()]<({<({}[()])><>({})<>}{}<><{}>)>)}{}

(courtesy of Stack Exchange user Mega Tom)