At the start of every school year, kids have to "get into the flow" again as they're bombarded with more and more subject matter and homework.

How can they make what they learn stick and not immediately forget it? There are three things parents need to be focussing on, says Rosa Schritt, a school teacher in Berlin who also helps pupils via online homework tutoring.

Find the right time

It starts with the right time for studying. While most parents tell their schoolchildren they can't play computer games until they've finished their homework, "it should be the other way around," remarks Schritt.

She says the amount of screen time should depend on the children's age, and when they're allowed to play computer games, they should start with them, followed by vigorous physical activity and then studying.

"The reason is that playing computer games causes the body to release [the steroid hormone] cortisol, a response to stress. This will 'overwrite' what was learned beforehand, which won't be retained," Schritt explains. Exercise can relieve stress, and what the child learns afterward can be consolidated during sleep.

Facilitate active learning

Children who acquire knowledge passively, by repeatedly reading, listening to, or looking at a subject matter, will know it by heart at some point, says Schritt, "but they probably won't be able to retain it for long or use it in answering complex questions."

So she recommends active learning. How?

"By creating outlines, marking important information in texts and jotting notes in the margins, and writing summaries," Schritt says. "Thinking up questions in relation to the material and then answering them is very effective too."

Children can actively learn vocabulary by pairing opposites, drawing pictures inscribed with the words to be learned, or hanging vocabulary flashcards throughout their home so they'll associate certain words with the cupboard or washing machine, for instance.

Get them to explain what they've learned

And if they study together with their schoolmates, they can explain the subject matter to each other, points out Schritt.

"They'll quickly find out whether they can explain it themselves, and in a way the others can understand. This allows errors to be cleared up fast."

Kids better understand something that they can express in their own words, she says, and this boosts their confidence.