11. MATHEMATICAL SIGNS
| + | Plus |
| − | Minus |
| ± | Plus or minus |
| Minus or plus | |
| × | Multiplied by[13] |
| ÷ | Divided by |
| = | Equal to |
| ≠ | Not equal to |
| ≡ | Identical with |
| Not identical with | |
| ≅ | Congruent to |
| Greater than | |
| Less than | |
| The difference between | |
| Is equivalent to | |
| ∫ | Integration |
| : and : : | Proportion |
| ∝ | Varies as |
| Approaches as a limit | |
| ∞ | Infinity |
| ∴ | Therefore |
| Because | |
| … | Continuation |
| √ | The radical sign |
| ⊥ | Perpendicular to |
| Factorial sign | |
| Parallel | |
| Arc of circle | |
| ° | Degree of circle |
| ′ | Minute of circle |
| ″ | Second of circle |
| ∠ | Angle |
| Right angle | |
| Square | |
| Rectangle | |
| Parallelogram | |
| Triangle |
[13] This is also indicated algebraically by a dot, as, a · b