How to improve focus amongst children

My child is not able to focus, gets distracted and is unable to concentrate and is very impatient.
This is one of the major concerns expressed by modern day parents bringing their children for assessment prior to admission to Melbourne Tutorials.
Other frequent observation as children complete their assessments.

• The child is unable to sit steadily and properly during the course of assessment lasting about 45 minutes.
• The child gets easily distracted and wants to go to toilet or asking for water or trying to move around on any pretext.
• The child tried to rush up his assessment and there are glaring and careless errors in spellings and Math assessments.

All the above indicators point toward a general lack of concertation in children.