#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define fi first
#define sec second
#define pii pair<ll,ll>
const ll N = 1e5 + 5;
const ll MOD = 1e9 + 7;
signed main(){
ios_base::sync_with_stdio(false); cin.tie(nullptr);
ll tc = 1;
// cin >> tc;
while(tc--){
ll q; cin >> q;
for(int i=1;i<=q;i++){
ll l,r; cin >> l >> r;
ll dist = r-l+1;
while(l >= 10){
string tmp = to_string(l);
ll cur = 0;
for(auto i : tmp) cur += (i - '0');
l = cur;
}
ll rem = dist / 9;
ll ans = 0;
for(int i=1;i<=(dist%9);i++){
ans += l;
l++;
if(l > 9) l = 1;
}
ll sum = 0;
for(int i=1;i<=9;i++){
if(l > 9) l = 1;
sum += l, l++;
}
ans += rem * sum;
cout << ans << endl;
}
}
}
