Первое:
var cookie = 25, milk = 10, coffee = 3;var count_cookie = 0.5, count_milk = 2, count_coffee = 5;var money = 50;
function ТчкЗпт(ч) { return String(ч).replace(".",","); }
document.write("Печенье в клеточку: " + cookie + " грн * " + ТчкЗпт(count_cookie) + " = " + ТчкЗпт(cookie * count_cookie) + "
");
document.write("Молоко бычье: " + milk + " грн * " + ТчкЗпт(count_milk) + " = " + ТчкЗпт(milk * count_milk) + "
");
document.write("Кофе: " + coffee + " грн * " + ТчкЗпт(count_coffee) + " = " + ТчкЗпт(coffee * count_coffee) + "
");
document.write("Наличка: " + money + "
");document.write("Сдача: " + (money - cookie * count_cookie - milk * count_milk - coffee * count_coffee));
Второе:
var a=85;
var n1=a%10;
var n2= (a - n1) / 10;
var a=851;
var n1=a % 10;
var n2= (a % 100 - n1) / 10;
var n3= (a - n2 * 10 - n1) / 100;
var a=8511;
var n1=a % 10;
var n2= (a % 100 - n1) / 10;
var n3= (a % 1000 - n2 * 10 - n1) / 100;
var n4= (a - n3 * 100 - n2 * 10 - n1) / 1000;