//author: Ahmet Alp Orakci
#include <bits/stdc++.h>
using namespace std;
using i64 = long long;
#define int i64
#define ONLINE_JUDGE
void solve() {
int l, r;
cin >> l >> r;
auto solver = [&](int x) -> int {
int a = x % 9;
return 45 * (x / 9) + (a * (a +1) / 2);
};
cout << solver(r) - solver(l -1) << "\n";
return;
}
signed main() {
#ifndef ONLINE_JUDGE
freopen(".in", "r", stdin);
freopen(".out", "w", stdout);
#endif
ios_base::sync_with_stdio(false);
cin.tie(NULL); cout.tie(NULL);
int t = 1; cin >> t;
for(int i = 1; i <= t; i++) {
solve();
}
return 0;
}
