symbol	name	keyboard
√	square root	ALT-251, ⌥ v
∛  ∜	cube root & quad root
÷	obelus (ah-bel-us), 6÷2=3	ALT-246, ⌥ /
×	product, multiplication, times, 5×4=20
𝑥	italics x
ℯ	base of natural logarithm e
𝒾	italics i, imaginary number
∘	function composition, as in f∘g
∫	Integral for calculus	⌥ b
≈	approximate, as in π ≈ 3.14	⌥ x
≠	not equal to, as in 1+1≠3	⌥ =
≡	modular arithmetic congruence
≅	geometry congruence
±	plus or minus	ALT-241, ⌥ +
∙	multiplication dot or bullet	ALT-0149, ⌥ 8
⟌	long division operator
≥	greater than or equal to	ALT-242, ⌥ >
≤	less than or equal to	ALT-243, ⌥ <
∪	UNION, interval notation, "Joining"	ALT-8746
⋂	INTERSECTION, interval notation, "overlap"	ALT-8745

symbol	name	keyboard
½	one half	ALT-0189
⅓	one third
¼	one fourth
¾	three fourths	ALT-0188

symbol	name	keyboard
x̄	x-bar sample mean	ALT-0189
p̂	p-hat proportion of a sample
ŷ	y-hat predicted outcome
μ	Mu, mean of a population	ALT-230, ⌥ m
σ	Sigma, population standard deviation	ALT-229, ⌥ w

symbol	name	keyboard
ℵ	Hebrew aleph, the cardinality of infinite sets that can be well-ordered	ALT-0189
¢	American money unit cent	ALT-0189
→	right pointing arrow
✓	basic check mark ✓good job!
∞	Infinity symbol, Lemniscate, pronounced (lem-nis-kit)	ALT-236, ⌥ 5
ƒ	italics f for functions	⌥ f
	Apple Computer Logo	⌥ K

symbol	name	keyboard
sin⁻¹	Inverse Sine
cos⁻¹	Inverse Cosine
tan⁻¹	Inverse Tangent
𝒻⁻¹(𝑥)	Inverse Function
°	degree	ALT-248, ⌥⇧8
∠, ⦜	angle & right angle
⟂	perpendicular angle symbol
△, ⊿	triangle, right-triangle	⌥ j