Partition whole numbers and decimals into 100s, 10s, 1s, tenths, etc. Students are asked to do this in more than one way.
http://www.mathsframe.co.uk/Partition3.swf

Other resources by this author can be found at:
http://www.mathsframe.co.uk/free_resources.asp

A matching game for number facts, decimal and fraction conversions, and measurement conversions.
http://www.mathsframe.co.uk/cardgame.swf

Other resources by this author can be found at:
http://www.mathsframe.co.uk/free_resources.asp

A fantastic interactive activity! Students get lots of practice at finding equivalent fractions, decimals and percents. Three thumbs up!

The website has a fact sheet, a worksheet, a quiz and (best of all) a game for teaching this activity.

The main website is at:
http://www.bbc.co.uk/skillswise/numbers/fractiondecimalpercentage/compar...

If you want to cut to the chase and just play the game, it can be found at:
http://www.bbc.co.uk/skillswise/numbers/fractiondecimalpercentage/compar...

A very versatile tool for learning about decimal number lines. Read the instructions on the home page first.

http://www.mathsonline.co.uk/freesite_tour/resource/whiteboard/decimals/...

Estimate the number that the pointer is pointing to, and then reveal the correct answer. You can choose whole numbers or decimals, and create your own number line if you wish. Click on [Begin] to start.

http://resources.oswego.org/games/Estimate/estimate.html

Click on the link below to download this flash activity, where students are asked to compare whole numbers, fractions or decimals. You can also create your own activities, including ordering measurements with different units.

http://www.topmarks.co.uk/r.aspx?sid=2452

Estimate the position of a given number on a number line. Levels 1 to 4 are whole numbers, while levels 5 to 8 are decimals.

http://www.oswego.org/ocsd-web/games/Estimate/estimate.html

Students play a version of Connect Four, gaining the chance to place a piece on the board by answering questions about simplify fractions, converting fractions to decimals and percents, as well as algebra questions involving fractions.

http://www.shodor.org/interactivate/activities/FractionFour/

Click on two cards to turn them over. If they match, they are cleared from the board. If not, they remain on the board. How many turns will it take you to clear the board?

http://www.interactivestuff.org/match/maker.phtml?featured=1&id=8

This is a flipchart with many interactive pages. You may need to become a member (its free!) of the Promethean Planet forum to access it.
http://www.prometheanplanet.com/us/server/show/ConResource.337

Go here to become a member of the USA Promethean Planet Forum:
http://www.prometheanplanet.com/us/server/show/nav.802