The Divisumma 18 marked a radical development for Mario Bellini. His intention was to produce a technological product that was totally humanized, almost playful, and that invited human touch. Olivetti in 1969 had already developed the bright-red Valentine portable typewriter, designed to be “taken to the countryside by Sunday poets”. Likewise infused by the Pop spirit of the age, the Divisumma 18 is unlike any calculator before or since. The bright yellow ABS plastic is covered by a yellow rubber “skin” that stretches over virtually the entire unit, and that gives it a soft appearance and feel. The rubberized keys depress and click with a springiness that is solid but fun at the same time.