Project for Calculating Population size

// full program time!
// predict the size of a population of organisms
// cin starting number of organisms, average daily population increase (percentage in decimal form), number of days that they will multiply
// loop used to display the size of the population for each day

// do not accept size of population <2, if user does anyway, display "The starting number of organisms must be at least 2.", display prompt again
//do not accept daily population increase < 0, display  "The average daily population increase must be a positive value."
//do not accept number of days < 1, display "The number of days must be at least 1."

/* more verbage:
Enter the starting number of organisms: Enter the average daily population increase (as a percentage): Enter the number of days they will multiply: On day 1 the population size was 22.
On day 2 the population size was 24.
On day 3 the population size was 27.
On day 4 the population size was 29.
On day 5 the population size was 32.
On day 6 the population size was 35.
On day 7 the population size was 39.
On day 8 the population size was 43.
On day 9 the population size was 47. */

//always 20, 0.1, and 10?

//starting off
#include <iostream>
#include <cmath>
using namespace std;

int main ()
{
//initializing variables for number of organisms given, average daily population increase, and number of days multiplying
	int startNumOrganisms;
	int	aveDailyIncrease;
	int numDaysMult;

//asking for the starting number of organisms
	cout << "Enter the starting number of organisms: ";
	cin >> startNumOrganisms;

// asking for the average daily population increase percentage
	cout << "Enter the average daily population increase (as a percentage): ";
	cin >> aveDailyIncrease;

// asking for the number of days they will multiply
	cout << "Enter the number of days they will multiply: ";
	cin >> numDaysMult;

// each day given? yikes. Define "day"?
	int day;

// defining population size for the population size found on each day
	int populationSize;

// limiting what I will accept for cin

// no startNumOrganisms under 2
// if the bastards cin something wrong anyway, this is what I will display:
	if (startNumOrganisms <2)
	{
		cout << "The starting number of organisms must be at least 2.";
	}

// no population increase less than 0, also the display
	if (aveDailyIncrease <0)
	{
		cout << "The average daily population increase must be a positive value.";
	}

//
	if (numDaysMult < 1)
	{
	cout << "The number of days must be at least 1.";
	}
// setting up the loop: using FOR loop
	for (day = 1; day >= numDaysMult && day <= numDaysMult ; day++)
	{
// calulating populationSize---> algebra: startNumOrganisms + (startNumOrganisms * aveDailyIncrease * day) = populationSize
		populationSize = startNumOrganisms * (day* startNumOrganisms * aveDailyIncrease);

// displaying the answers for each day
		cout << "On day " << day << "the population size was " <<populationSize <<". \n";

	}

return 0;
}