Adrian Bruce has a great Numeracy and Literacy website which contains so many great free games to download.
This link takes you to an addition section that contains:
- Doubles maths games
- Number facts with doubles plus one
- Addition basic facts game
- Addition four in a row
- Addition- What is the sum?
- Number Challenge- numbers - 10
- Maths poster addition vocabulary- plus, add, with, sum
- Cool Maths Game- addition basic facts