text: import math
  
  
  def age_band_5_years(age: int) -> str:
      """
      Place age into appropriate 5 year band
  
      This function takes the age supplied as an argument and returns a string
      representing the relevant 5 year banding.
  
      Parameters
      ----------
      age : int
          Age of the person
  
      Returns
      -------
      out : str
          The 5 year age band
  
      Examples
      --------
      >>> age_band_5_years(3)
      '0-4'
      >>> age_band_5_years(None)
      'Age not known'
      >>> age_band_5_years(95)
      '90 and over'
      """
  
      if age is None:
          return "Age not known"
  
      if age >= 90:
          if age >= 150:
              raise ValueError("The age input: {} is too large.".format(age))
          else:
              return "90 and over"
      elif age < 0:
          raise ValueError("The age input: {} is too low.".format(age))
      else:
          lowerbound = 5 * int(math.floor(age / 5))
          upperbound = lowerbound + 4
          return "{}-{}".format(lowerbound, upperbound)
  
  
  def age_band_10_years(age: int) -> str:
      """
      Place age into appropriate 10 year band
  
      This function takes the age supplied as an argument and returns a string
      representing the relevant 10 year banding.
  
      Parameters
      ----------
      age : int
          Age of the person
  
      Returns
      -------
      out : str
          The 10 year age band
  
      Examples
      --------
      >>> age_band_10_years(3)
      '0-9'
      >>> age_band_10_years(None)
      'Age not known'
      >>> age_band_10_years(95)
      '90 and over'
      """
  
      if age is None:
          return "Age not known"
  
      if age >= 90:
          if age >= 150:
              raise ValueError("The age input: {} is too large.".format(age))
          else:
              return "90 and over"
      elif age < 0:
          raise ValueError("The age input: {} is too low.".format(age))
      else:
          lowerbound = 10 * int(math.floor(age / 10))
          upperbound = lowerbound + 9
          return "{}-{}".format(lowerbound, upperbound)
  