Helping him stay calm

[inthename]

tips for keeping 13yr old ds calm on the day before non academic scholarship assessment please (its linked to being able to apply for a bursary, so feels a big thing to him)
current school have internal exams this week as well which isn't helping!

Have they said what he'll be doing during the day?

Exercise. Lavender on his pillow at night. Watch a funny film to relax. Eat healthy food which he likes.
(If he's really stressy I would try bach flower remedy (on the basis it won't do any harm)).

Try not to discuss it too much and definitely don't give hints and tips about what he should and shouldn't do on the day.
The less preparation you do the better in my opinion. Watching movies or playing computer games is a good way to distract him from thinking about the assessments. The more relaxed he is, the better and the best way to relax is to make as little fuss about it as possible (even if you have to reach for a glass of wine as soon as he departs for the assessments).