public class Format { public static String rublFormat(double sum) { String rubles; int mainPart = (int) sum; if (mainPart >= 100) mainPart %= 100; if (mainPart >= 20) mainPart %= 10; if (mainPart == 1) rubles = "рубль"; else if (mainPart < 5 && mainPart > 0) rubles = "рубля"; else rubles = "рублей"; return rubles; } }