Usually about 6-11 per night, depending on the individual. You will know how much sleep you need by how many hours you will sleep if you are not woken.
As a 15 year old i get about 5-6 hours of sleep. That's long for me but i also sleep at school. Yes i know its bad but im home schooled. 6-11 hours is way to long for any 15 year old.
about 8 to 10 hours of sleep
8 hours,,,...
12 hours
I'm quite sure they need at least 7 hours.
Children need 8 hours.
9 - 10 hours
8 - 10 hours.
Depends on the length of your "sleep cycles", but generally 7-9 hours.
10-11 hours every night are the optimum hours of sleep an eight-year-old should get.
if you mean how many hours you should sleep in a year it would be 3,650 hours of sleep for a regular year not a leap year
37
About 10-12 hours