My mom says we each need a certain amount of hours of sleep. I need 10 hours, my brother who is 5 needs 11 hours and my youngest sister who is 2 needs 12 hours. We figure out what time we must go to bed the night before if we need to get up at 8:00a.m. When school is on we have to get up by 7:00 so we need to go to bed earlier.