The rules that use the vocabulary item "hundred" are:

<hundreds_number>

<digit> hundred

<digit> hundred <tens_number-not_digit_sequence>

<distance>

<digit-not_zero> hundred

<digit-not_zero> hundred <number>

<scale_number>

two hundred fifty

two hundred and fifty

five hundred

two thousand five hundred

twenty five hundred

one hundred thousand

a hundred thousand

two hundred and fifty thousand

two hundred fifty thousand

five hundred thousand

<time_point_name>

<hour> hundred

<hour> hundred hours

<up_to_four_digits>

<number-not_digit> hundred

<two_digits>

hundred