#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define pll pair<ll,ll>
const ll MOD=1e9+7;
//#define ll int
//KALAU TAKUT RTE
bool cmp (pair<ll,ll> x, pair<ll,ll>y){
return x.second < y.second;
}
ll calc(ll x, ll y){
if (y==0) return 0;
ll ans=(y/9)*45 + ((1+(y%9==0?9:y%9))*(y%9) /2);
return ans;
}
signed main(){
ios_base::sync_with_stdio(0); cin.tie(0);
ll n; cin>>n;
while(n--){
ll a,b; cin>>a>>b;
if (a==0 || a-1==0){
cout<<(b/9)*45 + ((1+(b%9==0?9:b%9))*(b%9) /2)<<endl;
}
else cout<<(b/9)*45 + ((1+(b%9))*(b%9) /2) -
(((a-1)/9)*45 + ((1+((a-1)%9))*((a-1)%9) /2))<<endl;
}
}
