The rules that use the vocabulary item "three" are:
three
one three
twenty three
two three
three <up_to_six> <digit>
three
oh three
zero three
one three
twenty three
two three
three <up_to_six> <digit>
three
three
three
three <up_to_six> <digit>
three
three
three
three <up_to_six> <digit>