The idea of doing homework for three straight hours can be daunting, or even straight up terrifying! And this anxiety often causes a student to procrastinate. Which causes anxiety... It's a downwards spiral!
Help your student by setting a timer for 45 minutes. Doing homework for 45 minutes is a lot more managable then 3 hours. After their 45 minutes of homework, they can take a short break, check Snapchat, respond to text ;) and then lather, rinse, repeat!
Research shows taking frequent breaks helps stay motivated and focused. It also helps integrate memories, improves learning and fosters creativity.
For high school students I recommend taking a 5-10 minutes break every 45-60 minutes, depending on the student. For middle school students I recommend taking a 10 minute break every 30 minutes.
There are a lot of great multi-timer apps available that let you set two repeating timers. These timers will help your student stay focused while they are working and remind them to get back to work after their break!