Have the students organize their data so that they represent their data first using a bar graph. In this sense, the teacher can also discuss ratio and proportion. For example, let's say there are 40 total items in the pantry. It is helpful to break the circle into fourths, and then break it down further from that point. The graphs need to be attractive so they are easy to read, and proportional.
Students can manipulate the data so that they can make their graphs visually attractive.
I used the Claris Works program when I did this activity with my sixth grade class. It could easily be adjusted to be used with Microsoft Excel. After students input their own data, it is good for them to see how data can be represented in a variety of ways.