Here you can find the source of add(final Number a, final Number b)
public static BigDecimal add(final Number a, final Number b)
//package com.java2s; /*!//from ww w . j a v a2 s.c o m * This program is free software; you can redistribute it and/or modify it under the * terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software * Foundation. * * You should have received a copy of the GNU Lesser General Public License along with this * program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html * or from the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. * * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * See the GNU Lesser General Public License for more details. * * Copyright (c) 2002-2013 Pentaho Corporation.. All rights reserved. */ import java.math.BigDecimal; public class Main { public static BigDecimal add(final Number a, final Number b) { if (a instanceof BigDecimal) { final BigDecimal ab = (BigDecimal) a; return ab.add(new BigDecimal(b.toString())); } if (b instanceof BigDecimal) { final BigDecimal ab = (BigDecimal) b; return ab.add(new BigDecimal(a.toString())); } final BigDecimal ab = new BigDecimal(a.toString()); return ab.add(new BigDecimal(b.toString())); } }