Science Buddies: "Ask an Expert"

Hi, forum! Tomorrow my science fair project is due for 200 points. Scary huh? I've already done the Catching Stardust experiment here ---> https://www.sciencebuddies.org/science- ... #procedure
But I'm getting lost at step 16. I've taken pictures of my satellites but I'm not sure how to count the particles? I uploaded them to photoshop...what do I do next? Please answer as soon as possible, this is due tomorrow.

I'm sorry if this answer came too late...
But if you are finding it difficult to count every speck of dust in the circle, I would suggest dividing the circle into equal parts, then zooming in really close and estimating the number of particles in one section, and then multiplying that number to find the particles in the whole circle.