To concentrate is to direct one's mental efforts towards a particular activity. The level of concentration is, like for example intelligence, one of the elements that influence one's performance. Therefore it is important that people who need to perform are able to concentrate, especially children. However, parents know like no other that concentrating is often a challenging task for children.
Depending on the age of the child, concentration will be almost non-existent or more advanced. A child of 5 will have only a short span of attention. But once children reach the age of 9 or 10, they should be able to plan certain activities and remain concentrated on a task for a certain period.