NEW YORK (AP) — Shoppers can skip the math. It’s about to get easier to compare prices on products from breakfast cereals to toothpaste at some of the nation’s major online retailers.

New York’s attorney general said Tuesday that Costco, CVS, FreshDirect, Wal-Mart and Walgreen have agreed to list unit prices on their websites and mobile apps for shoppers nationwide in the coming months. Amazon.com Inc., the world’s largest online retailer, did not agree to participate, according to Attorney General Eric T. Schneiderman.