Vedic square
In Indian mathematics, a Vedic square is a variation on a typical 9 × 9 multiplication table where the entry in each cell is the digital root of the product of the column and row headings – in other words, each cell contains the remainder when the product of the row and column headings is divided by 9. Numerous geometric patterns and symmetries can be observed in a Vedic square, some of which can be found in traditional Islamic art.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | |
| 1 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
| 2 | 2 | 4 | 6 | 8 | 1 | 3 | 5 | 7 | 9 |
| 3 | 3 | 6 | 9 | 3 | 6 | 9 | 3 | 6 | 9 |
| 4 | 4 | 8 | 3 | 7 | 2 | 6 | 1 | 5 | 9 |
| 5 | 5 | 1 | 6 | 2 | 7 | 3 | 8 | 4 | 9 |
| 6 | 6 | 3 | 9 | 6 | 3 | 9 | 6 | 3 | 9 |
| 7 | 7 | 5 | 3 | 1 | 8 | 6 | 4 | 2 | 9 |
| 8 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 9 |
| 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 |
Algebraic properties
The Vedic Square can be viewed as the multiplication table of the monoid where is the set of positive integers partitioned by the residue classes modulo nine..If are elements of then can be defined as, where the element 9 is representative of the residue class of 0 rather than the traditional choice of 0.
This does not form a group because not every non-zero element has a corresponding inverse element; for example but there is no such that.
Properties of subsets
The subset forms a cyclic group with 2 as one choice of generator - this is the group of multiplicative units in the ring. Every column and row includes all six numbers - so this subset forms a Latin square.| 1 | 2 | 4 | 5 | 7 | 8 | |
| 1 | 1 | 2 | 4 | 5 | 7 | 8 |
| 2 | 2 | 4 | 8 | 1 | 5 | 7 |
| 4 | 4 | 8 | 7 | 2 | 1 | 5 |
| 5 | 5 | 1 | 2 | 7 | 8 | 4 |
| 7 | 7 | 5 | 1 | 8 | 4 | 2 |
| 8 | 8 | 7 | 5 | 4 | 2 | 1 |