A suitable setup is important to increase productivity, so try to remove distractions and have a calm working environment. 

Make sure there is enough space for your child to spread their work and equipment out; as well as space to stretch out occasionally.

Finally maintaining a correct posture is very important. Wherever your child sits, their feet should ideally be flat to the floor. If their legs aren’t quite long enough, consider using a footrest and if they are using a screen to complete their learning, such as a laptop or tablet or computer screen, their eyes should be level with the top of the screen to avoid straining their neck. If they are not tall enough to do so, use a height adjustable chair or use seat cushions to boost them up.