#include <bits/stdc++.h>
using namespace std;
string L, R;
string s;
int len;
long long memo[25][4][2];
long long dfs(int cur, int M, int f) {
  if (cur == len) return 1;
  if (memo[cur][M][f] != -1) return memo[cur][M][f];
  int v;
  if (f)
    v = s[cur] - '0';
  else
    v = 9;
  long long ans = 0;
  for (int i = 0; i <= v; i++) {
    if (i == 0)
      ans += dfs(cur + 1, M, f & (i == v));
    else {
      if (M == 3) continue;
      ans += dfs(cur + 1, M + 1, f & (i == v));
    }
  }
  return memo[cur][M][f] = ans;
}
long long solve(string& x) {
  s = x;
  len = s.length();
  memset(memo, -1, sizeof(memo));
  return dfs(0, 0, 1);
}
int chk(string& x) {
  int cnt = 0;
  for (int i = 0; i < x.length(); i++) {
    if (x[i] != '0') cnt++;
  }
  return (cnt <= 3);
}
int main() {
  int T;
  cin >> T;
  while (T--) {
    cin >> L >> R;
    cout << solve(R) - solve(L) + chk(L) << endl;
  }
  return 0;
}
