Actually, the ideal amount of sleep for children in elementary school is nine to ten hours per night. Like adults, they suffer when they don't get enough sleep. They can't concentrate on their schoolwork, they have trouble remembering things, they may become irritable and fidgety, and they may be vulnerable to colds and flu. Clearly, it's in your and their best interests to make sure they sleep well-and long every night. Don't allow their lives to set so full of sports. hobbies, and other activities that they can't get everything done without shorting themselves on sleep.
Regular exercise is good for children, but exercise too close to bedtime can interfere with sleep.
Set a schedule. Make sure they understand that complaining about bedtime isn't going to get them anywhere. Beware of caffeine. Many popular drinks, including colas, are loaded with caffeine, a stimulant that can affect sleep. Check the labels.