#include <bits/stdc++.h>
using namespace std;
int pw[4] = {1, 9, 81, 729};
long long com(long long n, long long k) {
  if (k == 0 || k == n)
    return 1;
  else if (k < 0 || k > n)
    return 0;
  else if (k == 1)
    return n;
  else {
    return com(n - 1, k - 1) + com(n - 1, k);
  }
}
long long get(long long n, long long k) {
  long long tot = 0;
  for (long long i = 0; i <= k; i++) {
    tot += com(n, i) * pw[i];
  }
  return tot;
}
long long cal(long long x) {
  stringstream ss;
  ss << x;
  string s = ss.str();
  long long len = s.length();
  int cnt = 3;
  long long res = 0;
  for (int i = 0; i < len; i++) {
    if (s[i] == '0')
      continue;
    else {
      res += get(len - i - 1, cnt);
      cnt--;
      if (cnt == -1) break;
      res += get(len - i - 1, cnt) * (s[i] - '1');
    }
  }
  return res;
}
int main() {
  int t;
  long long L, R;
  cin >> t;
  for (int i = 0; i < t; i++) {
    cin >> L >> R;
    cout << cal(R + 1) - cal(L) << endl;
  }
  return 0;
}
