you should always double check, like Kaplods said, sometimes it works in your benefit because of the fractions, like one slice of bread on the slider might be 2 but if you're eating a sandwich and using two it comes to 3. I can eat 2 packs of my oatmeal for 5 instead of 3 pts. for one.
Suite's favorite Progresso soup comes to mind in these discussions, 0 pts. per serving but sometimes 2 pts. for two servings...plus sometimes bonus after-affects
The bottom line is, try to be fair and honest with figuring out your points (you're only cheating yourself if you try and work around the system), I think a general rule of thumb is if you eat 2 at once you double everything and then figure it out, someone might even have a time thing, like 4 hours in between or something, I don't know...anyway, make sure you check the serving sizes on your labels and do the best you can, nobody's perfect, we're all learning things together.
My leader says if it's on the line it's the next higher value, sometimes I'm extra precise with that slider so it doesn't touch the line
best of luck
