#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define int long long
#define maxn 303
#define mi LLONG_MIN
#define ma LLONG_MAX
#define mod 1000000007
#define pb push_back
#define S second
#define F first
map<int, int> sums;
int sumd(int x) {
if (sums.find(x) != sums.end()) {
return sums[x];
}
if (x < 10) {
sums[x] = x;
return sums[x];
}
int sum = 0;
while (x > 0) {
sum += x % 10;
x /= 10;
}
sums[x] = sumd(sum);
return sums[x];
}
int32_t main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int q;
cin >> q;
map<int, int> mp;
vector<int> pref(10, 0);
for (int i = 1; i <= 9; i++) {
pref[i] = pref[i - 1] + i;
}
while (q--) {
int l, r;
cin >> l >> r;
int l1 = (l % 9 == 0 ? 9 : (l % 9));
int r1 = (r % 9 == 0 ? 9 : (r % 9));
int cnt = max(0LL, ((r - r1 - (l - l1 + 9)) / 9));
int suml = pref[9] - pref[l1 - 1];
int sumr = pref[r1];
if (r - l < 9) {
suml = pref[r1] - pref[l1 - 1];
sumr = 0;
}
cout << suml + sumr + cnt * pref[9] << endl;
}
}
