I signed my kids up for taking an upcoming SAT Reasoning Test (formerly the Scholastic Aptitude Test). For those who don't know, the SAT is a nationwide test used by colleges to evaluate students.
An interesting feature that they provide now (for free) is the "Official SAT Question of the day". It's available online and you can subscribe for email delivery.
I signed up for the email delivery and actually try to answer each question (and certainly don't get them all right). They seem to randomly alternate math and verbal questions. I find it a good bit of mental exercise for the old noggin and recommend the same for you as well (even if neither of us plan to take the SATs again, if ever).
Go ahead, give it a shot. It's free and it can stretch the mind.