This math book is very impressive. It opens the eyes of students that many things in life revolve around math and makes it fun and important to learn.IMPORTANT: Please Read:If you have an question about your item or problem with us for any reason we ask that you please contact us by email. eCRATER will seemingly innocently direct you toward filing a claim. Don't let this happen. Please allow us to resolve any problem to your satisfaction with you without eCRATER "assistance"eCRATER has developed a system utilizing poorly designed software to track possible issues with sellers. Once placed they are difficult to repair and potentially very harmful to us. Many times a client will have an innocent question that without intent of harm snowballs into a nightmare. We had a defect that eCRATER stated in a letter would be removed automatically that we recently finally had removed after 48 days and 500+ minutes on hold (8 hours) %#(&$#*!#Here's an example. A client inquired regarding the shipping of an item. We provided the tracking information and within 15 minutes he wrote back saying he was sorry the package had arrived four days ago and his roommate hadn't notified him. He offered and provided us a statement stating that it wasn't an error on our parts and he was very sorry. He went on to say that eCRATER directed him into clicking on a item not received claim when all he tried to do was contact us. An easy fix? NO! The "defect" remains on our record. The only way for us to resolve an issue like this and have the "defect" removed is to escalate a claim against you the buyer. Crazy? Absolutely, We are now forced to initiate actions against a fellow eCRATER member to protect our reputations and the harsh penalties sanctioned if a few of these "defects" occur. One example is increasing the shipping costs for buyers up to 40% higher. PLEASE CONTACT first without getting eCRATER involved. They mean well but life if controlled solely by computers can become a nightmare. Trust US It's the best for all of us. Thanks.