Weeks 4-5: Give wet or moistened dry food, mixed with formula to form a slush. Supplement with formula if the kitten is not taking to the new food, to make sure it gets enough calories. Weeks 5-6: The weaning kittens should start to nibble on the kibble, slightly moistened with water.
Montessori education begins in the Pre-K/Primary years. Enrollment in the San Francisco Public Montessori School begins at age 3 years in the Pre-K program. Children may enroll in either the PreK or the elementary program. The preschool, which is operated by the SFUSD Early Education Department, is a 2-3 year Pre-K/primary cycle.
I believe preschool is for younger children between the ages of 2 and 3. Pre-K would encompass those from 4 up to 5 yrs of age. Generally, parents won't register children in school when they are 5, these children will just enter regular kindergarten. It is really up to the parent and the school/academy they choose.