Sensitive period for numbers – This is the time when we introduce the math curriculum is introduced in a Montessori classroom. Counting used to be a part of language and at this period they are interested in numbers as an entity and a separate type of language.

More Montessori Sensitive Periods:

Sensitive Period for Order (age 18 months to 2 years)
Sensitive Period for Language (birth to 6 years)
Sensitive Period for Movement (birth to 4 years)
Sensitive Period for Refinement of the Senses (birth to 5 years)
Sensitive Period for Weaning (5 to 6 months)
Sensitive Period for Numbers (4 to 5.5 years)
Sensitive Period for Manners and Courtesies (2 to 6 years)