Maths

Dino Dig (adding)
http://www.fun4thebrain.com/addition/dinodigadd.html

Under the Shell (adding)

http://primarygamesarena.com/How-Many-Under-the-Shell751

Maths Bingo (adding)

http://www.abcya.com/math_bingo.htm

Flower Power (adding)

http://www.hbschool.com/activity/flower_power

Fishing (subtraction)
http://www.softschools.com/math/games/fishing_sub.jsp 
 
Alien Munchtime (subtraction) 
http://www.fun4thebrain.com/subtraction/luckysub.html

Fruit Shooting (subtraction)
http://www.sheppardsoftware.com/mathgames/fruitshoot/fruitshoot_subtraction.htm 

Bug Catcher

http://www.toyheater.com/bug-catcher.php

Counting Caterpillar

http://www.ictgames.com/caterpillar_slider.html

Duck Shoot

http://www.ictgames.com/newduckshoot.html

Pop That Balloon

http://funschool.kaboose.com/formula-fusion/carnival/games/game_math_popper.html

Practice your Doubles

http://www.ictgames.com/robindoubles.html

Writing Numbers

http://www.abclearningtime.com/123s7.htm