#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<ll, ll> pll;
typedef pair<ull, ull> pull;
typedef pair<ll, ll> pii;
typedef pair<ld, ld> pld;
ll get(ll x){
ll ret = x/9*45;
for(ll i = 1; i <= x%9; ++i)
ret += i;
return ret;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
//freopen("in.txt", "r", stdin);
//freopen("out.txt", "w", stdout);
ll q;
cin >> q;
while(q--){
ll l, r;
cin >> l >> r;
cout << get(r)-get(l-1) << '\n';
}
}
