#include <iostream>
#include <cmath>
#define ll long long
using namespace std;
int Q;
long long L, R;
long long ans;
int gauss(int l, int r){
int d = r - l + 1;
return ((r+l) * d) / 2;
}
long long answer(int x, int b){
long long ret = 0;
long long y = (x+b-2) % 9 + 1;
if (b / 9){
ret += 45*(b/9);
if (x != 1) ret += gauss(x, 9);
if (y != 9) ret += gauss(1, y);
}
else{
if (x + b > 9 && y - b < 1){
ret += gauss(x, 9);
ret += gauss(1, y);
}
else{
ret += gauss(x, y);
}
}
return ret;
}
int main (){
cin >> Q;
for (int i = 0; i < Q; i++){
cin >> L >> R;
ans = 0;
long long b = R - L + 1;
long long x = (L-1) % 9 + 1;
cout << answer(x, b) << endl;
// cout << L << " " << R << " " << x << " " << y << " " << answer(x, b) << " " << rans << endl;
}
}
