My son's teacher showed him this awesome site to help him learn area and perimeter called Mr. Nussbaum Learning +Fun. This site has lots of games but so far we have only played Zoo Designer and my kids have loved it.
In this game students are asked to create an exhibit with either a specific area or perimeter and then a blueprint grid for the exhibit. If the enclosure is the right size the animals will be happy and the student receives points, if it's wrong the animals can escape. If you make 2 mistakes the zoo keeper fires you. The game begins by asking for just a perimeter or an area then progresses to asking for the correct perimeter and area. Another bonus you can play the game multiple times because the numbers change each time you begin.
It is a really fun, short game. Kids need to be taught how to find perimeter and area before they can play the game because the game is not intended to teach them how to do it, just to give them practice in a fun way. All the answers are whole numbers so this game is meant for end of 3rd grade to mid 4th graders or as a review for the upper grades. There are ads on the page so remember to talk to your kids about not clicking on the links if they are playing alone.
Other ideas that can help kids learn about area and perimeter is to simply use these words in their every day life. Ask them real life problems like if I were to put a fence around the yard would I need to know the area or perimeter? What about grass, carpet, walls, tile. You could even have your kids clean up the area or perimeter of their rooms. Give them a ruler and have them find the area of the table, counter, rug, let them explore. Just remind them to round to the nearest whole number so they aren't working with fractions.