[Spanish version]
Curtis was explaining to Ian that his teacher told him to find all the squares in a 50x50 checkerboard. He said, "I started with smaller checkerboards and when I got to the 4x4 checkerboard I found 30 different squares." Ian said, "I think that was a good way to start. Now let's see if we can spot a pattern."


Question: If you have a checkerboard that is 50x50 with small squares inside it, how many squares will there be altogether?
Use this Java applet from the Freudenthal Institute to help you think about the question: http://www.fi.uu.nl/toepassingen/00213/toepassing_wisweb.en.html
Use the submit link below to get hints and also chances to revise.