Use for addition, subtraction -then discover how to set up for multiplication Math Facts Baseball - Practice addition and subtraction facts! There's a great statistics lesson in here too. This would really be a great project for any elementary grade.
cityscape - I love the black line drawing against the richly colored skies. * I think I would add colorful water below to balance it and show the "colorfulness" of nature contrasted by the black and white of the city.
Robots from boxes--definitely!" Not sure who that is, but ROBOTS. OH MY GOODNESS. This would be perfect as a collaborative project with an English teacher, if kids were to read a sci-fi, futuristic book that had robots.