Olly was very easily distracted, but he was really trying to keep his focus. Because he wasn't just responsible for brewing a potion for his own grade or benefit. He couldn't get distracted by looking at the others who had taken the potion because if he messed up that wouldn't be good for Sam. What would happen if he messed up drastically? Hopefully nothing bad. He assumed the professor would not have them make a potion in this situation if messing it up would result in dire consequences for the drinker. He seemed nicer than that.

He peered up at the board to follow the next step. Add two measures of standard ingredient. That wasn't hard. Olly did so quickly and looked back up at the board for the next step. 2 cups of water. He pulled out his wand. "Aguamenti." He filled up his measuring cup and added that to his cauldron, then did it again so he had added two cups in total to the potion.