( CNN ) -- Brittany Wenger learned about artificial intelligence during a seventh-grade school project . She was immediately enthralled , bought a book on programming and taught herself how to code . Now 17 , Wenger won the grand prize at the second annual Google Science Fair on Monday for her project on improving breast cancer diagnosis accuracy using artificial neural networks . That combination of drive , passion for science and a desire to do something good was common at this year 's event . Organizers of the online science fair received thousands of entries from 100 countries , including India , Ukraine , Malta and Swaziland . Google picked 15 finalists and , at a final gala in an airplane hangar in Palo Alto , announced the winners in three age categories , along with a grand-prize winner . Jonah Kohn , 14 , won first place in his age group for a project that helps people with hearing loss experience music through vibrations . A team of three 15- and 16-year-olds from Spain took home a trophy ( made entirely out of Legos ) for their look at the microscopic creatures that thrive in fresh water . Two 15-year-old young men from Swaziland researched hydroponic techniques to help subsistence farmers in their homeland , where food shortages are a devastating problem . They won the Science in Action award , which highlighted a project making a practical difference . Before the winners were announced , the finalists presented their projects one last time on the Google campus Monday afternoon . Groups of young kids from summer camps filed through to meet the young scientists and watch their demonstrations . Some Google employees even brought their children to work for the day just to see the event . In classic Silicon Valley fashion , many adults were there grilling presenters , just like they would any entrepreneur with a pitch . They asked tough questions about methodology , costs and results . Some even asked about business plans . One man urged finalist Rohit Fenn to make his eco-friendly toilet design , the Vacu-flush , open source . Fenn 's prototype uses a vacuum system that consumes 50 % less water than traditional toilets . Unfortunately , his design is still too cost-prohibitive to be made made without the help of established toilet manufacturers . `` They would need to take me seriously , which they wo n't because I 'm 16 years old , '' he said . The contest was free to enter and open to all students around the world between 13 and 18 years of age . Google collected entries from January to April and announced the finalists in May . The grand prize winner receives a $ 50,000 scholarship , an internship and a trip to the Galapagos Islands . For Wenger , one of the highlights of the experience was meeting famed computer scientist Vint Cerf , who talked with her at length about computer science and neural networks . For her winning project , Wenger wrote a program that improves diagnoses of malignant breast tumors by using a large amount of data stored online and looking for patterns . It 's an ambitious project that was made possible by that first spark of interest in programming five years ago . `` I decided that it was what I was going to do , '' said the Florida native . `` I 'm very persistent , and I learned to code , and I started coding neural networks that played soccer -- I 'm an avid soccer player as well . ''
Google announced the winners of its second annual science fair Monday . Grand prize winner is teen whose project improves accuracy of breast-cancer diagnoses . The contest was free and open to all students around the world between 13 and 18 .