Soft Schools
Soft Schools: Find the Missing Number Game
Students enter the missing number in a consecutive sequence of three integers. Score is kept.
Math Is Fun
Math Is Fun: Common Number Patterns
Developed by a mathematics teacher from the UK, this page identifies and illustrates several common number patterns.
Fun Brain
Fun Brain: Number Cracker (Number Series Game)
The Number Cracker needs you to help find a secret code by identifying the missing number in a series.