1. Oswego Math Magician Subtraction
http://oswego.org/ocsd-web/games/mathmagician/mathssub.html

2. Soccer Shoot Out. Single digit subtraction in horizontal layout.
http://www.funbrain.com/cgi-bin/fract.cgi?A1=s&A2=1&A15=0

3. Tic Tac Toe Challenge.Single digit subtraction in vertical layout.
http://www.funbrain.com/cgi-bin/ttt.cgi?A1=s&A2=1&A3=0

4. How Many Problems Can You Complete in 60 Seconds?
http://www.howe-two.com/free/FastMath/index.html

5. Basic Subtraction Facts from AAA Math.
- 0,1,2 Facts
http://www.aaastudy.com/sub26bx3.htm
-3 and 4 Facts
http://www.aaastudy.com/sub26bx4.htm
-5 and 6 Facts
http://www.aaastudy.com/sub26bx5.htm
-7 and 8 Facts
http://www.aaastudy.com/sub26bx6.htm
-9 and 10 Facts
http://www.aaastudy.com/sub26bx7.htm
All Subtraction facts for 0 through 10
http://www.aaastudy.com/sub26bx2.ht