Emma has $26 for her weekend expenses. She spent $12.81, including tax, on a new book. Additionally, she needs to set aside $10.00 for a lunch outing next week. If stickers cost $0.42 per package, tax included, describe the maximum number of packages (p) Emma can buy.
Emma has $26 - $12.81 = $<<26-12.81=13.19>>13.19 remaining after buying a new book.
She needs to set aside $10.00, so she has $13.19 - $10.00 = $<<13.19-10=3.19>>3.19 for the stickers.
Thus, Emma can buy a maximum of $3.19 / $0.42/package = <<3.19/0.42=7.595>>7 complete packages of stickers.
Emma can only buy a maximum of p = <<7=7>>7 packages of stickers. Answer: \boxed{7}.