The rules that use the category "<tens>" are:

<tens_number-pl>

<tens>

<tens> <digit-not_zero>

<tens_number-not_digit_sequence-pl>

<tens>

<tens> <digit-not_zero>

<tens_number-not_digit_sequence>

<tens>

<tens> <digit-not_zero>

<tens_number>

<tens>

<tens> <digit-not_zero>