#include<algorithm>
#include<iostream>
#include<cstring>
#include<vector>
#include<cmath>
#include<queue>
#include<stack>
#include<set>
#include<map>
#define endl '\n'
#define maxn 1005
#define ii int
#define ss string
#define ll long long
#define pii pair<int,int>
#define debug(a) cout<<(#a)<<" = "<<a<<endl
using namespace std;
const int N = 999;
ss s;
ii main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	ii T;
	cin >> T;
	for(ii i = 1; i <= N; i ++ )
	{
		ss s1;
		ii k = i;
		ii sum = 0;
		while(k)
		{
			s1 += (char)(k%10+'0');
			k /= 10;
		}
		ii len = s1.size();
		ss s2;
		for(ii k = len - 1; k >= 0; k -- ) s2 += s1[k];
		for(ii j = 1; j <= i; j ++)
		{
			s += s2;
		}
	}

	while(T --) 
	{
		ii l, r;
		cin >> l >> r;
		ll sum = 0;
		for(ii i = l; i <= r; i ++)
		{
			sum += (int)(s[i-1] - '0');
		}
		cout << sum << endl;
	}
}