My 5th grade group has been using ratios and ratio tables to better understand fractions and their equivalents. Here are two online activities (one game and one lesson) that support ratios & fractions. I hope my students--and yours--will try them out! :)
Ratio Blaster - In this free online game, view a ratio (example: 3 to 6) and click to shoot at the invading
spaceship that shows an equivalent ratio, written as a fraction
Cheesy Goldfish - Determine which goldfish cracker package is the better deal, using a ratio table to find price/ounce.