Even when school is out, learning still will be very much in.

Summer vacation, educators say, is no time for parents to let their kids forget about academics. Research has shown that if you don’t keep your child’s brain working during this interlude, she could lose, on average, 2.6 months of grade-level equivalency in math skills and as much as a year’s reading level.

The plunge is even more pronounced for children from low-income families, says Maria Antonia Pinon, director of the All Aboard Family Literacy Program at Miami’s nonprofit Institute for Child and Family Health,

So it’s in your child’s best interest to keep academically active. The good news? The brain can be challenged in a variety of ways that won’t cost too much money or prompt teeth-gritting resistance from the kids.

Pinon is a big advocate of recreational reading, both by adults and kids.

“Children learn by imitation,” she says. “If mom or dad reads, the child is going to follow suit. And if the child can’t read, read to him. Any kind of learning, when attached to love, will create a habit.”

What’s more, summer can be a way to expose children to difficult subjects in a new way, says Anne Rambo, associate professor of family therapy at Nova Southeastern University and author of “I Know My Child Can Do Better!” (McGraw-Hill, $9.99 in paper). Vacation is the perfect time for acquiring or building a passion, as well as for reviewing already-learned skills.

“Summer,” Rambo adds “is a great chance to help the child become a more fully developed person.”

Here are suggestions from experts to stop the summer brain drain:

• Plan your summer trip with an educational theme. Headed for Disney World? Stop at the Kennedy Space Center. If you’ve already decided on a particular town, look up national parks nearby and take the kids on a ranger-led geological or historical tour. Have them read a book about where you’re going before you leave.

• Recruit your child to help plan a vacation. Have her prepare a budget for spending money, and ask for help plotting the trip on a map and estimating miles using the map key. This is a built-in math lesson.

• During the trip, play “I Spy” to search road signs for numbers, colors and geometric shapes. For older children, estimate and calculate the travel time to your destination.

“This helps kids see the math all around them,” says Trena Wilkerson, associate professor of curriculum and instruction at Baylor University.

Before spending time outdoors, a parent can encourage the family to learn about the area’s wildlife. Use the Internet to look up native plants and animals, then check them off as you spot them during your visit.

• Teach your child how to keep statistics for summer sporting events like baseball. Kids can compute ERA, RBI and other percentages.

• Turn any activity at home into a teachable moment. For example, beading jewelry with a young child helps support pattern recognition and counting.

• Think of the kitchen as a math lab. Ask your child to help you cook and bake. The extra mess is well worth the effort of applying such math concepts as measuring and figuring out fractions. Make it a game, too, by asking: How many pints in a quart? Cinnamon is which country’s major export?

• Turn your home into an international destination by using the Web. Research your family’s heritage or a favorite foreign city.