Numbers First, Letters Second

Write a function that sorts list while keeping the list structure. Numbers should be first then letters both in ascending order.

Examples

num_then_char([
  [1, 2, 4, 3, "a", "b"],
  [6, "c", 5], [7, "d"],
  ["f", "e", 8]
]) ➞ [
  [1, 2, 3, 4, 5, 6],
  [7, 8, "a"],
  ["b", "c"], ["d", "e", "f"]
]

num_then_char([
  [1, 2, 4.4, "f", "a", "b"],
  [0], [0.5, "d","X",3,"s"],
  ["f", "e", 8],
  ["p","Y","Z"],
  [12,18]
]) ➞ [
  [0, 0.5, 1, 2, 3, 4.4],
  [8],
  [12, 18, "X", "Y", "Z"],
  ["a", "b", "d"],
  ["e", "f", "f"],
  ["p", "s"]
]

Notes

Test cases will contain integer and float numbers and single letters.