Games that build mathematical skills:
Mr. Anker's Tests
Cool Math 4 Kids this site has tons of games. It's fun for both kids and adults. Some of the games are really too difficult for first graders, so keep an eye on what they are doing. My suggested games are below:
Hooda Math this site has tons of games. There are some addition, subtraction, and logic games that first graders can play. Some of the games get into very complicated mathematics, so it would be useful for older students as well. It was designed by a middle school math teacher.
Addition Practice at Internet4classrooms links to lots of good games.
Subtraction Practice at Internet4classrooms links to lots of good games.
Illuminations these activities are from the National Council of Teachers of Mathematics. This link will take you to the K-2 activities, but activities are available for all grades k-12.
ICT Games this is an English site, so avoid the money section! There are some games and some teaching tools. You will probably need to help your child for a few minutes the first time they play a new game.
Arcademic Skill Builders this website has arcade-like games that practice several skills. The addition and subtraction games are good for first grade. The site seems to default to the multiplication games, so students will have to make sure they check which section they are in. Some of the games are multiplayer, but there is no way for anyone to contact your child. It does ask for players to enter their name. This is a good place to start teaching internet safety because there is no risk: encourage your child to use a nick name or initials only, they can also just use the name the computer assigns.
ABCya There are literacy games, math games, and fun activities all on the same page at this site. Most of the math games students can practice counting by any number, adding and subtracting. These games are easy to figure out and engaging. For some more challenging games go to the second grade section. Kids will enjoy "math man."
Sheppardsoftware has lots of math activities for every level. Thanks to Mrs. Spoelstra for introducing me to this site! The Early Math section is great for students who need to work on one-to-one in their counting.
Kidport--lots of activities for all subject areas. Click on the grade level of your choice, then choose a subject.
XtraMath You will need an enrollment code. This was sent home on 12-5-13.