Final answer:
Frobel developed 'Gifts' and 'Occupations' as materials for children's free play in his Kindergarten.
Step-by-step explanation:
The materials that Frobel developed for children's free play in his Kindergarten were called "Gifts" and "Occupations". The Gifts were a series of wooden blocks of different shapes and sizes that children could use to build and create. The Occupations consisted of activities and exercises that allowed children to engage in hands-on learning, such as drawing, cutting, folding, and weaving.