Subtangent is a website well worth a visit; it provides several flash games including a few which mimic the letters and the numbers rounds from the Countdown TV show.

The Subtangent website was produced by Duncan Keith, a Maths teacher here in England (UK).

The "Numbers and Letters" game is available at http://www.subtangent.com/maths/numbers-and-letters.php...

For...

• Literacy lessons – choose a mixture of vowels and consonants and then see who can make the longest word from the ...

A matrix shows 100 or 25 problems (depending upon the game chosen). Users can choose...

• additions, or
• subtractions, or
• multiplications.

The target number is above the matrix.

Press/click/tap on the field, in the matrix, that matches the target number.

With a correct choice, the field will change colour. The aim of the user/class (if used on an interactive whiteboard [IWB]) is to try to get

• either five coloured fields in a row (if the 5 TIC TAC GO game is chosen) or
• three coloured fie...

Super Math Games has some limited free games that work very well on Interactive White Boards (IWBs). 

Click on the “guest” login.  The free games are indicated by the green check marks;

Free games include...

• Algebra
  • Quadratic Equations
  • Sequences
  • Shaded Regions
• Data
  • Stem & Leaf
  • Tallying
  • Tree Diagrams
• Number
  • Negative Numbers
  • Number Lines
  • Percentages 1 & 2
• Shape
  • Measuring Angles
  • Perimeter
  • Pythagoras' Theorem
• Kids
  • Percentages
  • Place Value
  • Probability
• Expert
  
  • Logarithms
  • Quadratics
  • Radian...