Good news for parents: There is one simple thing you can do to boost your kids’ chances of getting better exam or test scores. It doesn’t involve extra classes or nagging, and it’s not at all unpleasant. In fact, it’s something most people look forward to, and it’s called sleep.

Several studies have linked sleep and academic performance, but a joint study by two Montreal universities specifically examined sleep in relation to report card grades, and found that children with greater “sleep efficiency” performed better in math and languages.

According to clinical psychologist Reut Gruber, lead author of the study, sleep efficiency is the proportion of the amount of time one sleeps to the amount of time one spends in bed. “Simply put, you go to bed, you lie down and spend time in bed, but if you’re not able to sleep through the time in bed, that’s not efficient sleep,” she explains.

This quick checklist, recommended by the University of Michigan Health System, can help you determine if your child is sleeping efficiently:

• Can your child fall asleep within 15-30 minutes?
• Can your child wake easily at the time he/she needs to get up?
• Is your child awake and alert all day, or does he/she need a nap?

If you answered “no” to any of the above questions, you may need to examine your child’s sleeping habits. Children aged 7-12 are thought to need 10–11 hours of sleep on average, but in reality, few school-going children in Singapore would be able to clock those hours. If you’re unable to bring bedtimes forward, the next best thing you can do is ensure your child’s quality of sleep is not compromised. Here’s how:

The right light, at the right time.

Before artificial light was invented, people based their sleep and wake patterns on available daylight, as well as seasonal changes in sunrise and sunset times. Some researchers have suggested that to promote a regular sleep-wake cycle, it’s important to have exposure to natural light in the morning—and throughout the day, if possible. Along the same lines, they recommend dimming or minimising artificial lighting in the evening, to signal to the body that it’s time to produce more melatonin, a hormone that helps regulate sleep.

Serve sleep-friendly foods at dinner.

We’re all familiar with the slump that we land in right after a heavy meal. What if we could induce that feeling in our kids after dinner? As it turns out, we can. There are foods that promote sleep; these are foods that contain a substance called tryptophan. Tryptophan helps your body produce a brain chemical, serotonin, which is then used to make the sleep hormone melatonin. Foods that are high in tryptophan include bananas, dairy products, and poultry. But, to be truly effective, tryptophan-rich foods should be paired with carbohydrates to trigger the reactions that will eventually lead to sleep.

Say goodnight to your devices.

The relationship between screen time and sleep is complicated, as screen time can affect sleep in direct and indirect ways. When kids use devices close to bedtime, sleep becomes less inviting than what’s happening on the screen. And as kids put off bedtime preparations (such as brushing their teeth), bedtimes get pushed back even further. It’s also been thought that device use during the day affects sleep by cutting into the time spent moving about and exercising—activities which help one to feel sleepy at the end of the day.

One should also consider the content being viewed on devices. Anything exciting, dramatic, or frightening can lead to the release of hormones like adrenaline, which results in wakefulness. Couple this with the fact that a device is also a light source, which inhibits the production of the sleep hormone melatonin, and it’s not hard to understand why device-savvy kids tend to sleep late. The solution? Set reasonable limits on screen time. In the past, health authorities have advised parents to limit screen time to no more than two hours a day, for children older than two, although new recommendations may emerge as we grow more dependent on technology. If limiting screen time for the day is challenging, aim for no electronics an hour before bedtime.

Take “lights out” seriously.

Most kids go to bed before their parents do; if you live in an apartment, this means there’s often light filtering into your children’s bedrooms as they sleep. Although it seems harmless, at least one study has shown that chronic exposure to light can elevate one’s level of the stress hormone cortisol, which has been linked to depression and lowered cognition. It appears we’d all function better if we slept in complete darkness, so go ahead and get rid of the night lights, turn off devices or put them in sleep mode, and close bedroom doors if necessary.

Cut out caffeine.

Kids don’t have coffee cravings, but this doesn’t mean they’re not consuming caffeine. Caffeine is present in sodas, bottled and canned teas, chocolate and coffee ice cream, and certain medications. Check food labels, especially in the evenings, to make sure your child isn’t eating or drinking something that may keep him/her up all night.