-----------------------------
|  old |unknown|weight|digit| 
-----------------------------
| units|       |     1|     |
-----------------------------
|  tens|       |    10|     |
-----------------------------
|number|       |      |     |
-----------------------------
-----------------------------
| new  |unknown|weight|digit| 
-----------------------------
| units|       |    10|     |
-----------------------------
|  tens|       |     1|     |
-----------------------------
|number|       |      |     |
-----------------------------