From the current view (datasheet view) change the field size property for the rastudentid field to 4
a) Right-click on the field header rastudentid and select Properties. Then, navigate to the Field Size property and input 4.

b) Access the Design View of the database, locate the rastudentid field, and adjust the Field Size property to 4.

c) Click on the rastudentid field in the datasheet view, go to the Format tab, and select Field Size from the options. Enter 4 as the desired field size.

d) Open the rastudentid field properties directly from the datasheet view, find the Field Size property, and set it to the value 4.