divmod10() : a fast replacement for /10 and %10 (unsigned)

Personally, I would love to see it wrapped in a function which, for purposes of this post, I shall call digit().

Example use of digit():
long n = 4216738;
byte ones = digit(n, 0);  // now, ones == 8
byte tens = digit(n, 1);  // now, tens == 3
byte hund = digit(n, 2);  // now, hund == 7
byte thou = digit(n, 3);  // now, thou == 6
byte myri = digit(n, 4);  // now, myri == 1
byte lakh = digit(n, 5);  // now, lakh == 2
byte mill = digit(n, 6);  // now, mill == 4
byte cror = digit(n, 7);  // now, cror == 0

This would be extremely useful for displays.

I'm not sure how it should behave for negative numbers, though.