Important Common Maths Symbols
Symbol  Symbol Name  Meaning  Example 
+  Plus sign  Addition  2 + 3 = 5 
−  Minus sign  Subtraction  3 − 2 = 1 
×  Times sign  Multiplication  4 × 2 = 8 
*  Asterisk  Multiplication  4 * 2 = 8 
∙  Multiplication dot  Multiplication  4 ∙ 2= 8 
÷  Division sign  Division  4 ÷ 2 = 2 
/  Division slash  Division  4 / 2 = 2 
–  Horizontal line  Division / fraction  
±  Plus  minus  Both plus and minus operations  4 ± 3 = 7 and 1 
∓  Minus  plus  Both minus and plus operations  4 ∓ 5 = 1 and 9 
=  Equals sign  Equality  7 = 2 + 5 
≠  Not equal sign  Inequality  3 ≠ 4 
>  Strict inequality  Greater than  6 > 3 
<  Strict inequality  Less than  4 < 7 
≥  Inequality  Greater than or equal to  6 ≥ 4 
≤  Inequality  Less than or equal to  3 ≤ 5 
( )  Parentheses  Calculate expression inside first  4 × (3 + 2) = 20 
[ ]  Brackets  Calculate expression inside first  [(1 + 3) × (1 + 2)] = 12 
.  Period  Decimal point, decimal separator  1.26 = 1 + 26/100 
a^{b}  Power  Exponent  3^{3 }= 27 
Square root  
Cube root  
%  Percent  1% = 1/100  10% × 50 = 5 
~  Approximately equal  Weak approximation  10.7 ~ 10 
≈  Approximately equal  Approximation  x ≈ y means x is approximately equal to y 
∝  Proportional to  Proportional to  y ∝ x when y = kx, where k is a constant 
⇒  Implies  This implies  x = 2 ⇒ x^{2} = 4 
⇔  Equivalent  If and only if (iff)  
∀  For all  ∀ x >1, x^{2 }> x  
∃  There exists  ∃ x such that x^{2 }> x  
∴  Therefore  a = b ∴ b=a  
∵  Because / since  Since a^{2 }= 25, a = 5 
Common Set Symbols
Symbol  Symbol Name  Meaning  Example 
{ }  Set  A collection of elements  A ={1, 2, 4, 5}
B = {4, 5, 6} 
A ∪ B  Union  Objects that belong to set A or set B  A ∪ B = {1, 2, 4, 5, 6} 
A ∩ B  Intersection  Objects that belong to set A and set B  A ∩ B = {4, 5} 
A ⊆ B  Subset  Set A has fewer elements or equal to the set B  {4, 5, 6} ⊆ B 
A ⊂ B  Proper subset  Set A has some elements of set B  {4, 5} ⊂B 
A ⊄ B  Not a subset  Set A is not a subset of B  {1, 6} ⊄ A 
A ⊇ B  Superset  Set A has more elements or equal to the set B  {1, 2, 4, 5} ⊇{1, 2, 4, 5} 
A ⊃ B  Proper superset  Set A has more elements than set B  {1, 2, 4, 5} ⊇{1, 2, 4} 
A ⊅ B  Not a superset  Set A is not a superset of set B  {1, 2, 4, 5} ⊅{5, 7} 
A = B  Equality  Both sets A and B have the same members  {1, 2, 4, 5} = (1, 2, 4, 5} 
A×B  Cartesian product  Set of all ordered pairs from A and B  {1,2} × {3,4} = {(1,3), (1,4), (2,3), (2,4)} 
A^{c}  Complement  All the objects that do not belong to set A  A^{c} = {3, 6} when U = {1, 2, 3, 4, 5, 6} 
A  B  Difference  Objects that belong to A and not to B  {1, 2, 4, 5} − {4, 5} = {1,2} 
a∈A  An element of  The element a is in set A.  4 ∈ {1, 2, 4, 5} 
x∉A  Not an element of  The element a is not in set A.  6 ∉ {1, 2, 4, 5} 
A  Cardinality  The number of elements of set A  A = {1, 2, 4, 5}, A=4 
Ø  Empty set  Ø = { }  {1, 2} ∩ {5 ,6} = Ø 
U  Universal set  Set of all possible values  Normally, universal set in mathematics is the set of real numbers R. 
N  Natural numbers  N = {1, 2, 3, 4,...}  1 ∈ N 
W  Whole numbers  W = {0, 1, 2,3,4,5,...}  0 ∈ W 
Z  Integer numbers set  Z = {…3, 2, 1, 0, 1, 2, 3…}  7 ∈ Z 
Q  Rational numbers set  Q = {x  x = a/b, a, b∈ Z }  2/5 ∈ Q 
R  Real numbers set  R = {x  ∞ < x <∞}  6.353535 ∈ R 
Common Geometry Symbols
Symbol  Symbol Name  Meaning  Example 
∠  Angle  A figure formed by two rays.  ∠ABC = 30^{o} 
∟  Right angle  An angle which is equal to 90º.  ∠ABC = 90^{o} 
Δ  Triangle  Triangle shape  ΔABC has 3 sides. 
^{ o}  Degree  1 turn = 360^{ o}  360° makes a full circle. 
Line  Infinite line  The infinite line that includes A and B: 

Line segment  Line from point A to point B  The line between A and B: 

Ray  Line that start from point A  The line that starts at A, goes through B and continues on: 

Arc  Arc from point A to point B  
⊥  Perpendicular  Perpendicular lines (90º angle)  AC ⊥ BC 
  Parallel  Parallel lines  AB  CD 
≅  Congruent to  Same shape and size  ∆ABC ≅ ∆XYZ 
~  Similarity  Same shapes, not same size  ∆ABC ~ ∆XYZ 
x  y  Distance  Distance between points x and y   x  y  = 5 