Math puzzle: Fresh gridflowers

Math puzzle: Fresh gridflowers Skip to content Subscribe today Every print subscription comes with full digital access Subscribe Now Menu All Topics Health Humans Anthropology Health & Medicine Archaeology Psychology View All Life Animals Plants Ecosystems Paleontology Neuroscience Genetics Microbes View All Earth Agriculture Climate Oceans Environment View All Physics Materials Science Quantum Physics Particle Physics View All Space Astronomy Planetary Science Cosmology View All Magazine Menu All Stories Multimedia Reviews Puzzles Collections Educator Portal Century of Science Unsung characters Coronavirus Outbreak Newsletters Investors Lab About SN Explores Our Store SIGN IN Donate Home INDEPENDENT JOURNALISM SINCE 1921 SIGN IN Search Open search Close search Home INDEPENDENT JOURNALISM SINCE 1921 All Topics Earth Agriculture Climate Oceans Environment Humans Anthropology Health & Medicine Archaeology Psychology Life Animals Plants Ecosystems Paleontology Neuroscience Genetics Microbes Physics Materials Science Quantum Physics Particle Physics Space Astronomy Planetary Science Cosmology Tech Computing Artificial Intelligence Chemistry Math Science & Society All Topics Health Humans Humans Anthropology Health & Medicine Archaeology Psychology Recent posts in Humans Health & Medicine GLP-1 microdosers are chasing longevity By Jamie Ducharme5 hours ago Archaeology A new study questions when people first reached South America By Tom MetcalfeMarch 19, 2026 Health & Medicine Are pig organs the future of transplantation? 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Gridflowers are planted in square plots. Each autumn, they cast seeds to all neighboring squares, including diagonals. The next spring, the old flowers are gone. A fresh flower will grow only in the spots that had exactly two neighboring flowers the year before (see examples below). And true to its name, a gridflower won’t grow beyond a given grid plot. But the couple doesn’t want hand-planted gridflowers. They want flowers that grew naturally from the spread of the previous year’s flowers. Therefore, you must plant your four gardens by hand this summer, so that next summer, each one contains a desired number of gridflowers. How can you achieve the following number of flowers for each garden next year? • Exactly eight flowers for a 3 × 3 grid • Exactly 12 flowers for a 4 × 4 grid • At least 17 flowers for a 5 × 5 grid • At least 24 flowers for a 6 × 6 grid Looking for answers? Go to sciencenews.org/puzzle-answers. We’d love to hear your thoughts. Email us at puzzles@sciencenews.org. Questions or comments on this article? E-mail us at feedback@sciencenews.org | Reprints FAQ About Ben Orlin Ben Orlin is the author of Math with Bad Drawings. Popular Stories Neuroscience Why is math harder for some kids? Brain scans offer clues By Lily BurtonFebruary 27, 2026 Animals Wild monkeys invaded Florida. Should people protect them? By Freda KreierMarch 16, 2026 Animals Sharks are ingesting drugs in the Bahamas By Joshua Rapp LearnMarch 18, 2026 Science News Science News was founded in 1921 as an independent, nonprofit source of accurate information on the latest news of science, medicine and technology. Today, our mission remains the same: to empower people to evaluate the news and the world around them. It is published by the Society for Science, a nonprofit 501(c)(3) membership organization dedicated to public engagement in scientific research and education (EIN 53-0196483). 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