[MikeM]

You could buy some 2.5s and stick 'em in your gym bag is one solution. Edit: Oop! Josh beat me to it!

I would not do sets of 8 across (all sets the same weight) and raise 10 pounds at a time as that will get hard real quick. Same with just adding another set and trying to hit more reps.

If it was me and I had to jump 10 pounds at a time and wanted to use 8s, I'd ramp the sets. So, start low and build up to your set of 8. If you can do 150 for 8, start with 8x 100, 110, 120. The next week go to 110, 120, 130, and so on. You should progress for a good whil on that. If you miss 8 reps in the last set try again the next week, if you still can't do it, go back and start again, but this time heavier to start with.

You could do the same thing with sets of 3 or 5 or whatever. Just change the weights for the sets upwards as there are less reps.

But, in my opinion ramping is easier to deal with than sets across or simply adding sets on the end when making biggish jumps in weight.

Good luck!