There are so many free resources on the internet. The trick is figuring out which ones are worth your time.
The 4th through 6th graders started out using Khan Academy to learn to code. The enthusiasm around school was refreshing. Now all of our 3rd through 6th graders are learning Math with Khan Academy. This was all started by a specialist on my team that teaches in our computer lab. If you'd like to read more about it, she recently did a guest blog post for me here.
Khan Academy can be a great motivating early finisher activity. If you are looking for a free math website, that motivates kids, I highly recommend it. (They haven't asked me to say any of this.)
Recently some of our 5th grade girls were at an ALPs event and I made these signs for them. They had a great time sharing their coding skills with people from around our district.
Maybe you'll find a use for them as well. :) Download them here.
What are your favorite free math websites?