#include <bits/stdc++.h>
using namespace std;
long long cnk[20][20];
int pow1[4];
long get(long long len, long long k) {
  long ans = 0;
  for (long long i = 0; i <= k; i++) {
    ans += cnk[len][i] * pow1[i];
  }
  return ans;
}
long long count(long long a) {
  string s = to_string(a);
  int cnt = 3;
  long long ans = 0;
  for (int i = 0; i < s.length(); i++) {
    if (s[i] == '0') continue;
    ans += get(s.length() - i - 1, cnt);
    cnt--;
    if (cnt == -1) break;
    ans += get(s.length() - i - 1, cnt) * (s[i] - '1');
  }
  return ans;
}
int main() {
  pow1[0] = 1;
  pow1[1] = 9;
  pow1[2] = 81;
  pow1[3] = 729;
  for (int i = 0; i < 20; i++) {
    for (int j = 0; j < 20; j++) {
      if (j == 0 || i == j)
        cnk[i][j] = 1;
      else if (i > j) {
        cnk[i][j] = cnk[i - 1][j - 1] + cnk[i - 1][j];
      }
    }
  }
  int t;
  cin >> t;
  while (t--) {
    long long l, r;
    cin >> l >> r;
    cout << count(r + 1) - count(l) << endl;
  }
  return 0;
}
