Final answer:
In ASL, changing the handshape to represent a number while signing a measure word like 'week' is known as numeral incorporation, a grammatical process that expresses specific quantities.
Step-by-step explanation:
The process in American Sign Language (ASL) where you can change the handshape from a 1 to a 2, or a 3 and so on to mean a specified number of weeks is known as numeral incorporation. In ASL, numeral incorporation is a grammatical process where a number sign is integrated into the sign of a measure word, such as "week," to convey a specific quantity.
For example, by changing the handshape to indicate '3' while signing 'week,' a person can express the concept of 'three weeks' in one fluent movement. This efficient and concise form of communication is one of the many ways ASL allows for the expression of complex ideas through hand gestures.