Tuesday, April 20, 2010

MAM Day 20: Graphs, charts & visual math

Some of us are visual learners, but most students are able to read and extract information from charts and graphs by the time they reach middle school. Charts and graphs are visual representations of data "represented by symbols, such as bars in a bar chart, lines in a line chart, or slices in a pie chart". I'm sure most, if not all of you, have seen a chart at some point this past week, or even earlier today. Charts are everywhere! On the internet, magazines, newspapers, in school textbooks, on billboards, in all kinds of advertising, on TV, on the bus, and all points in between.

The results of CNN's online poll today

One of my favorite websites with funny charts and graphs where I got quite a few of my graphs for today. The main charts that we see the most in everyday life are pie charts, bar graphs, line graphs, and sometimes venn diagrams. I'll just briefly talk about each one and why they're used.

Pie charts represent a percentages in relation to each other. Usually pie charts are used in tallying 100% of a quantity. See my Billboard pie chart for a better example. The pie chart shows the proportion of pop music that was on the top charts vs. gangsta rap. Pie charts are often used to show a very quick picture of the selections. Out of the listed charts, I would have to say pie charts are the most simple, easy to glimpse at, but limited in what kinds of information they can show.

Well labeled bar graphs can show an amazing amount of information in a single graph. Most often, bar graphs are used to compare frequencies, or how many, of a category of data. Bar graphs can even show multiple sources of the same data, for example the graph below:
Shows the number of students over a period of time and breaks the data down into the number of boys in comparison to the number of girls.

Line graphs show a continuous source of data, someone's budget over the course of a month for example. At the beginning of the month, I posted a line graph of the number of people who visited my blog. This one is a line graph of the same thing, only a different time period. As you can see, the first day was a big increase over the previous number of hits and significantly more than my following days. The line graph shows progression of visitors over time and lets me know which of my posts are more interesting than others. Line graphs are only line graphs if the data has a progression usually over time.

Venn diagrams show an intersection of commonalities. Although venn diagrams aren't often used, they show groups of people, objects, or ideas and then show where other groups of people, objects, or ideas have common links. A proportion of Set A will not have shared characteristics of Set B, but there is a certain area where they do match up. I find venn diagrams don't show hard data, but illustrate concepts quite well.


1 comment:

  1. I love all the funny charts and graphs you posted! These are really great and a fun way to get kids more involved in math.

    Anyone wanting to learn more about bar graphs and histograms should check out my related blog post: