#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pll pair<ll, ll>
#define pii pair<int, int>
#define fs first
#define sc second
#define pb push_back
#define int ll
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int q;
cin >> q;
while (q--)
{
int l, r;
cin >> l >> r;
l--;
int a = l / 9, b = l % 9, n = r / 9, m = r % 9;
int suml = (a * (a + 1) / 2) + (b * (b + 1) / 2), sumr = (n * (n + 1) / 2) + (m * (m + 1) / 2);
// cout << sumr << " " << suml << " ";
cout << sumr - suml << "\n";
}
}
