good website that students can visually see groups of fractions. It has explanations for equivalent fractions, reducing, improper and proper, multiplying and addition of fractions.
This activity takes you step-by-step through the process of working out a fraction of a quantity. For example, to find 4/5 of 35 it will first ask you to enter the answer to 35 divided by 5, then move on to ask you what is 7 times 4. There's a numberline at the bottom to help.
In this game from Count On you practise finding a fraction of a number. You can play it as a two-player game or a single player can play against the computer.