#include<bits/stdc++.h>
#define ll long long
#define endl "\n"
#define fi first
#define se second
#define pb push_back
#define pll pair<long long, long long>
#define loop(i,n) for(int i=1;i<=n;i++)
#define loop0(i,n) for(int i=0;i<n;i++)
using namespace std;
//pbds template
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
//using namespace __gnu_pbds;
//template <class T>
//using ordered_set = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;
ll calc(ll a){
ll ans = a/9 * 45;
for(int i=1;i<=(a%9);i++){
ans += i;
}
return ans;
}
void solve(){
int tc;
cin >> tc;
for(int q=1;q<=tc;q++){
ll l,r;
cin >> l >> r;
cout << calc(r)-calc(l-1) << endl;
}
}
int main(){
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int tc = 1;
// cin >> tc;
while(tc--){
solve();
}
}
