Manga High has lots of cool games, including Pyramid Panic and Save Our Dumb Planet, which you can play for free to test your maths knowledge.
Maths Goodies offers free interactive lessons, worksheets, games, puzzles and homework help for all the different areas of mathematics.
An interactive site from Channel 4 for students, aged 11-16, of Maths.
A National Grid for Learning (NGFL) approved site containing links to free resources for Primary School level maths.
A National Grid for Learning (NGFL) approved site with puzzles and resources for all levels of study.
Skoool.co.uk is a website packed with interactive resources to help you learn Maths and Science at Key Stage 3 and 4
Create your own puzzles including maths squares, cryptogram and number blocks (and word puzzles). These can be printed out for classroom or home use.
Hundreds of free photocopy-able maths worksheets including fractions, time, shape and space.
Hotbits can provide genuine random numbers, generated by radioactive decay.
At 10 Ticks you can have fun with Maths, just click on the 'STUDENTS' tab to start. There are also bits to keep Teachers and Parents happy, as well.
Math Interactive is a Canadian website that provides interactive multimedia activities about all aspects of Mathematics