add
+
subtract
multiply
×
divide
÷
less than
<
greater than
>
equal
=
not equal
almost equal
number
#
positive
+1, +2, …
negative
-1, -2, …
fraction
¼, ½, …
decimal
0.25, 0.5, …
percent
%
square root
exponent
x2, x3, x4, …
pi
π
angle
right angle
triangle
parallel
perpendicular
similar