#include<stdio.h>
long long int dp[2][2];
long long int count(long long int n, long long int v)
{
	long long int d;
	dp[0][0] = 1;
	dp[0][1] = 0;
	for (d = 1; d <= n; d *= 10);
	for (d /= 10; d > 0; d /= 10)
	{
		dp[1][0] = dp[1][1] = 0;
		if (n / d % 10 > v)
			dp[1][1] += (dp[0][0] + dp[0][1]) * (v + 1);
		else
		{
			dp[1][1] += (dp[0][0] + dp[0][1]) * (n / d % 10);
			dp[1][1] += dp[0][1];
			dp[1][0] += dp[0][0];
			dp[1][1] += dp[0][1] * (v - n / d % 10);
		}
		dp[0][0] = dp[1][0];
		dp[0][1] = dp[1][1];
	}
	return dp[0][0] + dp[0][1];
}
long long int res[16];
long long int cal(long long int n)
{
	long long int i;
	for (i = 0; i < 10; i++)
		res[i] = count(n, i);
	for (i = 9; i > 0; i--)
		res[i] -= res[i - 1];
	long long int ans = 0;
	for (i = 0; i < 10; i++)
		ans += i * res[i];
	return ans;
}
void solve()
{
	long long int l, r;
	scanf("%lld %lld", &l, &r);
	printf("%lld\n", cal(r) - cal(l - 1));
	return;
}
int main()
{
	int t;
	scanf("%d", &t);
	for (; t > 0; t--)
		solve();
	return 0;
}