Shows inexact calculation issues with double

Inexact.java

package scrap.stackoverflow;

import java.math.BigDecimal;
import java.math.RoundingMode;

public class Inexact {
	
	static double roundToTwoPlacesA(double n) {
	    final double m = Math.rint(100 * n);
	    return m / 100.0;
	}
	
	static double roundToTwoPlacesB(double n) {
	    final long m = Math.round(10000000.0 * n);
	    final double x = 0.00001 * m;
	    final long r = (long) Math.rint(x);
	    return r / 100.0;
	}
	
	static double roundToTwoPlacesC(double n) {
		return BigDecimal.valueOf(n).setScale(2, RoundingMode.HALF_EVEN).doubleValue();
	}
	
	private static void checkMath(BigDecimal amountB, BigDecimal taxB) {
		double amountD = amountB.doubleValue();
		double taxD = taxB.doubleValue();
		
		BigDecimal    rawB = amountB.multiply(taxB);
		BigDecimal resultB = rawB.setScale(2, RoundingMode.HALF_EVEN);
		double     resultD = roundToTwoPlacesB(amountD * taxD);
		
		String strB = resultB.toString();
		String strD = BigDecimal.valueOf(resultD).setScale(2).toString();
		if (!strB.equals(strD)) {
			System.out.println("Failed for " + amountB + " * " + taxB + " = " + strB + " vs " + strD);
			System.out.println("Raw result : " + rawB + ", Double.toString(): " + Double.toString(resultD));
		}
	}
	
	public static void main(String[] args) {
		for (int rateInt = 1; rateInt < 1000; rateInt++) {
			BigDecimal rate = BigDecimal.ONE.setScale(20).divide(BigDecimal.valueOf(rateInt), RoundingMode.HALF_EVEN);
			for (int cents = 123456; cents < 123456 + 100000; cents++) {
				BigDecimal amount = new BigDecimal(cents).scaleByPowerOfTen(-2);
				checkMath(amount, rate);
			}
		}
		
		System.out.println("Nothing found...");
	}
}