Not sure where to start? These are the lessons and games we recommend most to students, parents and teachers on Basic-mathematics.com. Each lesson explains the topic in plain language, walks you through worked examples step by step, and ends with practice so you can check your understanding. Pick one below, or use the menu to find lessons on fractions, algebra, geometry, statistics and more.
The symbols used in school math, each with its meaning and an example. Search, or pick a topic.
70 symbols
| Symbol | Meaning | Example |
|---|---|---|
| + | plus, addition | 3 + 4 = 7 |
| − | minus, subtraction | 9 − 5 = 4 |
| × | times, multiplication | 6 × 3 = 18 |
| · | multiplication dot | 6 · 3 = 18 |
| ÷ | division | 12 ÷ 4 = 3 |
| / | fraction bar, divided by | 3⁄4 = 3 ÷ 4 = 0.75 |
| ± | plus or minus | x = ±3 means x = 3 or x = −3 |
| ( ) | parentheses, for grouping | 2 × (3 + 4) = 14 |
| [ ] | brackets, for grouping | 2[5 − (1 + 2)] = 4 |
| … | and so on | 2, 4, 6, 8, … |
| Symbol | Meaning | Example |
|---|---|---|
| = | is equal to | 5 + 2 = 7 |
| ≠ | is not equal to | 5 ≠ 7 |
| ≈ | is approximately equal to | π ≈ 3.14 |
| ≡ | is identical to (equal for every value) | 2(x + 1) ≡ 2x + 2 |
| < | is less than | 3 < 8 |
| > | is greater than | 8 > 3 |
| ≤ | is less than or equal to | x ≤ 5: x is 5 or less |
| ≥ | is greater than or equal to | age ≥ 18: 18 or older |
| ∝ | is proportional to | y ∝ x means y = kx |
| Symbol | Meaning | Example |
|---|---|---|
| an | a to the nth power (exponent) | 2³ = 2 × 2 × 2 = 8 |
| √ | square root | √25 = 5 |
| ∛ | cube root | ∛27 = 3 |
| % | percent (out of 100) | 25% = 25⁄100 = 0.25 |
| |a| | absolute value (distance from 0) | |−7| = 7 |
| −a | the opposite of a | the opposite of 6 is −6 |
| a : b | ratio of a to b | 3 : 4 (3 cats for every 4 dogs) |
| a | b | a divides b | 4 | 12, because 12 ÷ 4 = 3 |
| GCF | greatest common factor | GCF(12, 18) = 6 |
| LCM | least common multiple | LCM(4, 6) = 12 |
| π | pi, about 3.14 | C = πd |
| ∞ | infinity | 1, 2, 3, … goes on to ∞ |
| x̄ | mean (average) | for 2, 4, 9: x̄ = 5 |
| ∴ | therefore | x + 2 = 5, ∴ x = 3 |
| Symbol | Meaning | Example |
|---|---|---|
| { } | set braces | A = {1, 2, 3} |
| ∈ | is an element of | 2 ∈ {1, 2, 3} |
| ∉ | is not an element of | 5 ∉ {1, 2, 3} |
| ⊂ | is a subset of | {1, 2} ⊂ {1, 2, 3} |
| ∪ | union (in either set) | {1, 2} ∪ {2, 3} = {1, 2, 3} |
| ∩ | intersection (in both sets) | {1, 2} ∩ {2, 3} = {2} |
| ∅ | empty set | {even numbers between 2 and 4} = ∅ |
| Symbol | Meaning | Example |
|---|---|---|
| ∠ | angle | ∠A |
| ∠ABC | angle ABC (vertex B in the middle) | ∠ABC = ∠CBA |
| m∠ABC | the measure of angle ABC | m∠ABC = 40° |
| ° | degree | a right angle measures 90° |
| ∟ | right angle mark | marks a 90° corner in a drawing |
| ⊥ | is perpendicular to | AB ⊥ CD |
| ∥ | is parallel to | AB ∥ CD |
| △ABC | triangle ABC | △ABC has vertices A, B and C |
| ≅ | is congruent to (same shape and size) | △ABC ≅ △DEF |
| ∼ | is similar to (same shape) | △ABC ∼ △DEF |
| AB | line segment AB | has endpoints A and B |
| AB | ray AB | starts at A and goes through B |
| AB | line AB | goes on forever both ways |
| Symbol | Meaning | Example |
|---|---|---|
| A | area | rectangle: A = l × w |
| P or p | perimeter | square: P = 4s |
| C | circumference | C = πd |
| V | volume | box: V = l × w × h |
| S.A. | surface area | cube: S.A. = 6s² |
| L.A. | lateral area | cylinder: L.A. = 2πrh |
| B | area of the base | prism: V = Bh |
| b | base length | triangle: A = ½bh |
| b1, b2 | the two bases of a trapezoid | A = ½(b1 + b2)h |
| h | height | rectangle: A = bh |
| l | length, or slant height | rectangle: P = 2l + 2w |
| w | width | rectangle: A = lw |
| s | side length | square: A = s² |
| r | radius, or rate | circle: A = πr² |
| d | diameter, or distance | d = 2r |
| t | time | d = r × t |
| m | slope of a line | y = mx + b |
No symbols match your search.
Share this page