Image from the National Library of Virtual Manipulatives: Fractions, Ratio and Percentages. (NLVM site)
Multiplying and dividing by powers of 10 (10, 100, 1000, etc) is an important skill that will help you to work out decimals, percentages and converting measurements. You can use a number slider to work out the problems here.
Here are the rules for converting fractions to decimals and percentages. Try the BBC Skillwise Fractions, Decimals and Percentages game. A video on how to change fractions and decimals to percentages here. Some more interactive maths games about fractions, decimals and percentages.
My American colleague, Mrs Laguna, is also a member of Quia, where you can create any of thirteen different activities (from battleship to scavenger hunts), as well as quizzes and surveys. As well as creating your own activities, as a member you can browse the activites of other teachers.
Here are a few for my year 9 Science class to try:
Electricity and Magnetism – Who want to be a Millionaire?
And for year 7 Maths (decimals, fractions and percentages):
Ordering decimals and Ordering decimals 2.0
Fraction to decimal conversions