there are 10 solutions with "1" at the bottom (6-o'clock position) with numbers in ascending order:
1,2,3,4
1,2,3,6
1,2,3,8
1,2,5,6
1,2,5,8
1,2,7,8
1,4,5,6
1,4,5,8
1,4,7,8
1,6,7,8
there are 10 further solutions by adding 1 to each number in the solutions above- e.g. 1,2,3,4 becomes 2,3,4,5
there are 3 solutions with "3" at the bottom (6-o'clock position) with numbers in ascending order:
3,4,5,6
3,4,5,8
3,6,7,8
there are 3 further solutions by adding 1 to each number in the solutions above- e.g. 3,4,5,6 becomes 4,5,6,7
two further solutions are:
5,6,7,8
6,7,8,9
that makes 28 solutions so far.
for each solution- a further solution has the top and bottom numbers transposed- so 1,2,3,4 becomes 3,2,1,4.
for each solution- a further solution has the left and right numbers transposed- so 1,2,3,4 becomes 1,4,3,2.
for each solution- a further solution has both the top and bottom and the left and right numbers transposed- so 1,2,3,4 becomes 3,4,1,2.
so for each of the 28 solutions presented there are 3 'variations'- that gives a total of 112 solutions.