This puzzle was crafted by Tom Lensch. No need to speak about him because I assume that everybody already knows how good his craftmanship is.
Number blocks is composed of 4 pieces of wood with protrusions that fit inside a box. Each piece has a number on its top and the goal is to rearrange the numbers, hence the name.
Below on the left the starting position and on the right the solved position:
I see you coming and wonder how can these pieces move. Well the number 4 does not have any protrusions and thus you can just take it out, which creates a hole in the tray to be able to move the other pieces. Simple as that!
The moves are smooth and it's really fun to play with this puzzle and notice that at some point you're stuck....whatever you do you cannot achieve what you want...and that will prevent you from solving the puzzle :-)
I tried many combinations and was always stuck. Damn! How is it possible?! Well it is, but there is a clever features that you need to use!! And you will have to think out of the box! And no force (even small) is needed nor advised.
So after the puzzle is solved you can still try to arrange the pieces to find other combinations. If there were no protusions at all you could have 24 possbilities. For example (1st two numbers for top row and last two numbers for bottom row): 1234, 1243, 1324, 1342, etc.
Actually you have fewer possibilities due to the constraints of the pieces. I managed to find all the possibilities:
These extra challenges are not really difficult, but it's still fun to try to see how we can increase the fun of a puzzle. I am almost sure that no other combinations can be found, but in case you find others feel free to add a comment :-)
To conclude: a really nice and enjoyable puzzle for a reasonable price.