We live in a world where information is at our fingertips 24/7. I know sometimes students struggle with math, so why not put YouTube to a greater use than watching funny cat videos or people falling off of skateboards?
There are literally thousands of tutorial videos for any and all math concepts on YouTube. If you're student needs help at home, and you don't feel like you can help them, encourage them to watch tutorial videos over the material they are having trouble with!
There are also websites like KhanAcademy, that have tutorial videos and practice problems in all areas of math.
With so much help available, it's hard to justify the old "I didn't know what to do" excuse.