Color theory primary colors work at all is that the imperfect pigments being used have sloped absorption curves, and thus change color with concentration. A pigment that is pure red at high concentrations can behave more like magenta at low concentrations. This allows it to make purples that would otherwise be impossible. Likewise, a blue that is ultramarine at high concentrations appears cyan at low concentrations, allowing it to be used to mix green. Chromium red pigments can appear orange, and then yellow, as the concentration is reduced. It is even possible to mix very low concentrations of the blue mentioned and
SCALE-UP boards nearby. Each team has a laptop in case they need web access. The original design called for 11 round tables of nine students, but many schools have smaller classes while a few have even larger ones. Smaller classes, particularly those in high schools, have also been using D-shaped tables that seat six students. SCALE-UP SCALE-UP is a learning environment specifically created to facilitate active, collaborative learning in a studio-like setting. Some people think the rooms look more like restaurants than classrooms. The spaces are carefully designed to facilitate interactions between teams of students who work on short, interesting tasks.