Use geoboards, square shaped crackers or candy bars to calculate area. Place the items as you would tiles, filling up the space that you have marked. Count how many items it takes to completely fill the space.
Children can have fun with the challenge of creating a label for their answer, since the result will not be measured in feet, inches, centimeters, or any other conventional measure. Perhaps the label could be square candies? Square crackers?
Children can then measure the space occupied conventionally, calculate the area using paper squares of a known size and then convert their answer to square feet inches or centimeters, depending upon the measure of the paper squares.