Math Symbols

The "math" contained within this blog ranges from the purely mathematical equation (e.g., takt time, average) to metrics (e.g., inventory turns, order fill) to pseudo-mathematical (e.g., change management, waste elimination effectiveness) to concept introduction (e.g., hypothesis tests) to data and math integrity considerations (e.g., gauge repeatability and reproducibility, measurement system validation). So, the reader is bound to run into formulas, symbols, and mathematical definitions.

We try to keep things as simple as possible. Nevertheless, the following table of mathematical symbols may serve as a handy reference.

Category

Symbol

Name

Definition

Example

Basic Math

 =

equals sign

equality

 7 = 4+3
 >

strict inequality

greater than

 7>6
 <

strict inequality

less than

 7<8
 ≥

inequality

greater than or equal to

 7≥6
 ≤

inequality

less than or equal to

 7≤8
 ( )

parentheses

calculate expression inside first

 3x(4+1) = 15
 []

brackets

calculate expression inside first

 [(3+2)x(2+5)]=35
 +

plus sign

addition

 3+2=5
 -

minus sign

subtraction

 5-2=3
 x

times sign

multiplication

 3x5=15
 /

division slash

division

 8/2=4
 ¯

horizontal line

division/fraction

 Picture1
ab

power

exponent

 32=9
 √

square root

  √9=±3

Algebra

 { }

braces

set

 

 Picture5

floor brackets

rounds number to lower integer

 Picture6
Picture2 

ceiling brackets

rounds number to upper integer

 Picture3
 

nearest integer

rounds positive number to nearest integer

 
 |x|

single vertical bar

absolute value

 |-3|=3
 (a,b)

open interval

 

 

 ∑

sigma

summation – sum of all values in a range or series

sigma

Probability and statistics

 P(A)

probability function

 

probability of event A

 P(A)=0.7
P(A∩B)

probability of events intersection

probability of events A and B

 P(A∩B)=0.7
P(AUB)

probability of events union

probability of events A or B

 P(AUB)=0.7
 P(A|B)

conditional probability

probability of event A given event B occurred

 P(A|B)=0.5
Picture4

overbar or bar

sample average

Picture3