Here are a few of the free children's educational games available at http://www.adders.org/freeware/index.html.
 

Counting Frame

A simple abacus to help with counting up to one hundred. Can be used for adding, subtracting and other sums.
 

Pooh Snap

All the characters appear in the game which is played by matching pairs as in the traditional "snap" game.
 

Press A Letter

A simple game that shows pictures, sounds, music and short videos when a letter key is pressed on the keyboard.
 

Tell The Time

Click a Question button and the time is spoken to you. Set the hands to the right time and core points for getting it right.
 

Go Mouse

A simple game to help new computer users get to grips with basic mouse control.

Tidy Up

Click on items to tidy them away and watch them fly through the air "Mary Poppins" style.

 

Doodle Pad

A simple drawing and colouring program which includes stamps (small pre-drawn pictures to colour) of Winnie The Pooh, Piglet, Tigger, Owl, Rabbit, Gopher, Roo and Kanga to add to your pictures.