#include <bits/stdc++.h>
using namespace std;
int sumDigits(long long num) {
long long sum = 0;
while (num > 0) {
sum += num % 10;
num /= 10;
}
if(sum>9){
return sumDigits(sum);
}else{
return sum;
}
}
int main(){
int q;
cin>>q;
while (q--)
{
long long l,r;
cin>>l>>r;
long long awal=sumDigits(l);
long long akhir=sumDigits(r);
long long yang_akan_dikurangi;
if(r%9!=0){
yang_akan_dikurangi=(((r+(9-(r%9)))-(l-(l%9)))/9)*45;
}else{
yang_akan_dikurangi=(((r)-(l-(l%9)))/9)*45;
}
cout<<yang_akan_dikurangi-(((awal-1)*(awal))/2)-((9-akhir)*(10+akhir)/2)<<endl;
}
}
