155535

I worked out to get the smallest possible solution, you need to put the worms head on 32 (the smallest number on the shaded grid) and its body above it so it sits on 32,24,14 and 4 which equals = 76. To get the biggest solution you need to put the worms head on 67 and the body below it on 67,77,87 and 97 this = 328.
I worked out that there are 32 solutions for each box. I found this out because there are 8 different ways that the worm can be positioned and you can make 4 worms, so 4x8=32.