While kids are looking forward to a long break from school, parents are wondering how to put that time to good use. A study by Dr. Harris Cooper, professor of psychology at the University of Missouri-Columbia, found that students lose one to three months worth of learning over a typical summer vacation. But how do you avoid brain drain without sucking the fun out of summer?

Math is the biggest subject to take an academic hit during the summer months. Dr. Susan Canizares, senior vice president and publisher of educational publishing company Houghton Mifflin Harcourt, suggests having your child track his or her favorite sports team to keep his or her brain practicing math skills, critical thinking, and analytical skills. Teaching kids to cook can sharpen math skills as well (recipes are full of fractions), and planting and tending a summer garden is a hands-on science lesson waiting to happen.

There are plenty of websites at which children at all ages can hone their skills while having fun as well. Whether you're looking to help your child catch up with certain subjects, trying to teach your child to read, helping your tween ahead in school, or searching for ways to supplement your homeschooling curriculum, the games, printables, and other offerings at these websites are a great place to start.

Exploratorium. The physical Exploratorium is housed inside San Francisco’s Palace of Fine Arts and was founded by Dr. Frank Oppenheimer; the web version sprawls over 18,000 pages and hundreds of scientific subjects. A kid could get (wonderfully) lost without every having to leave her desk.

Funbrain. Kids learn most easily when they’re playing, which is one reason why Funbrain is popular with parents and teachers alike. The teacher’s page directs you to practical things like flash cards and curriculum guides, but parents who are looking to give their children a more casual learning experience can head right on over to the free games section.

Enchanted Learning. Enchanted Learning offers easy-to-digest printables for preschoolers and kindergarteners, as well as plenty of craft ideas tucked in among the lessons. The picture dictionaries are especially cool for budding linguists

The Kids Know It Network. This site allows kids to explore a number of subjects, from human biology to spelling to astronomy; there's also a database of free, downloadable songs in MP3 format to help kids reinforce what the kids are learning. The site's animal database is a great virtual trip to the zoo!

PBSkids. Tying in to Public Broadcasting classics like “Sesame Street” and “Arthur” as well as newer educational programs like “Word Girl” and “Super Why,” PBSkids.org offers games that are so much fun, little kids won’t even notice they’re learning.

Scholastic. There so much here that it's hard to know where to start. Scholastic has compiled an amazing teacher's resource that parents can also use for free, with subjects and lessons geared for everyone from pre-kindergarteners all the way through 12th graders. Browse by grade and subject, and be sure to check out the red-starred offerings.

How are you hoping to combat brain drain this summer?

Lylah M. Alphonse is a Globe staff member and mom and stepmom to five kids. She writes about juggling career and parenthood at The 36-Hour Day and blogs at Write. Edit. Repeat. E-mail her at lalphonse@globe.com.