Rounding number to a certain position

#include<stdio.h>
#include<math.h>
double roundToInteger(double), roundToTenths(double), roundToHundreths(double), roundToThousandths(double);
void main()
{
	double x, roundToInteger(x), roundToTenths(x), roundToHundreths(x), roundToThousandths(x);
	int count = 1, num, count1 = 1;
	while (count != 0)
	{
		printf("Enter how many numbers you want to process: ");
		scanf_s("%d", &num);
		count1 = 1;
		while (count1 <= num)
		{
			printf("Enter a floating point number: ");
			scanf_s("%lf", &x);
			printf("Original number was: %lf\nNumber rounded to an integer is: %lf\n", x, roundToInteger(x));
			printf("Number rounded to the nearest tenth is: %lf\nNumber rounded to the nearest hundredth is: %lf\n", roundToTenths(x), roundToHundreths(x));
			printf("Number rounded to the nearest thousandth is: %lf\n\n", roundToThousandths(x));
			count1++;
		}
		printf("Do you want to continue? Enter 0 to end and 1 to continue: ");
		scanf_s("%d", &count);
	}
}
double roundToInteger(double x)
{
	double y;
	y = floor(x + 0.5);
	return y;
}

double roundToTenths(double x)
{
	double y;
	y = floor(x * 10 + .5) / 10;
	return y;
}

double roundToHundreths(double x)
{
	double y;
	y = floor(x * 100 + .5) / 100;
	return y;
}
double roundToThousandths(double x)
{
	double y;
	y = floor(x * 1000 + .5) / 1000;
	return y;
}