class StringBuilderUtil {

    public static void format2f(@NonNull StringBuilder sb, float x) {
        final int x100 = Math.round(x * 100);
        final int whole = x100 / 100;
        final int tenths = x100 / 10 % 10;
        final int hundredths = x100 % 10;
        sb.append(whole);
        sb.append(".");
        sb.append(tenths);
        sb.append(hundredths);
    }

}