Measure elapsed time

#include <iostream>
#include <chrono> // steady_clock
#include <cstdlib> // rand(), srand()
#include <ctime> // time()
using namespace std;

// Time how fast you can multiply two numbers.
int main()
{
    srand(time(NULL)); // Prepare random number generator.
    int first_random_number = 0; // first number to multiply.
    int second_random_number = 0; // first number to multiply.

    // Explain the program.
    cout << "You will be given two numbers to multiply together.\n"
        "\nTime yourself to see how fast you can do it.\n";
    cout << "\nPress enter to see the numbers.\n"
        "Press enter again when you have the answer.\n"
        "You will see the correct answer and your time.\n";
    cout << "\nPress ENTER when ready.\n";
    cin.ignore(numeric_limits<streamsize>::max(), '\n'); // Wait till ready.

    first_random_number = (rand() % 89) + 11; // Generate first number to multiply.
    second_random_number = (rand() % 9) + 1; // Generate second number to multiply.

    cout << first_random_number << " * " << second_random_number << '\n'; // Display the problem.
    chrono::steady_clock::time_point start = std::chrono::steady_clock::now(); // Start timing.

    cin.ignore(numeric_limits<streamsize>::max(), '\n'); // Wait till user is done.
    chrono::steady_clock::time_point stop = std::chrono::steady_clock::now(); // Stop timing.

    float elapsed_time = std::chrono::duration_cast<std::chrono::milliseconds>(stop - start).count(); // Calculate elapsed time.
    float elapsed_time_seconds_decimal = elapsed_time / 1000; // Convert milliseconds to seconds.

    cout << "The answer is " << first_random_number * second_random_number << '\n'; // Display the answer.
    cout << "\nYour time: " <<  elapsed_time_seconds_decimal << " seconds\n"; // Display how long it took.

    return 0; // End the program.
}