Number Klotski - a fun puzzle

This number puzzle - Number Klotski is a variant from the traditional Klotski puzzle, it may be addictive, please take a rest when it is needed.

It may be just a few seconds working out the 3x3 challenge; it may requires quite a number of minutes solving the 9x9, it is possible to continue from last play, so you can work it out with few sessions instead of one.

The rule is relatively simple:
- Only one empty square, make good use of it.
- Every other blocks were assigned a unique number.
- Only one block or few continuous blocks could be moved towards the empty square at a time.
- Your mission: bring the blocks back to numerical order, from left to right, top to bottom.

Please let me know if you have suggestions or questions!