Himuro's dialogue is covering too much for me to make out what's on the blackboard there. It's not particularly visible in the other picture either. Given the first kanji is for groups and the surrounding context, I imagine it's about putting groups together for tasks, but...
You roadside pebbles had I been there I would be insulted but in full agreement
Likewise.
Himuro-kun...Cultural FestivalClass'sHey, over he~re
How much of a budget did they give us for the cultural festival~?Hey, you
I don't remember granting you permission to speakAlright, listen up, you roadside pebblesWhat, you some kind of dictator now...?Dividing Tasks
GroupWe're now going to decide on what our class is doing for the cultural festival
Only those with ideas are permitted to speakThe cultural festival, huh...
I'm not really good with this kind of thing
All that peer pressure for, like, "Let's all pitch in together~"...