{"id":4055,"date":"2025-12-03T08:00:27","date_gmt":"2025-12-03T13:00:27","guid":{"rendered":"https:\/\/mathvoices.ams.org\/mathmedia\/?p=4055"},"modified":"2025-12-03T10:23:59","modified_gmt":"2025-12-03T15:23:59","slug":"math-digests-october-2025","status":"publish","type":"post","link":"https:\/\/mathvoices.ams.org\/mathmedia\/math-digests-october-2025\/","title":{"rendered":"Math Digests October 2025"},"content":{"rendered":"<h2 style=\"text-align: left\">October digests:<\/h2>\n<ul>\n<li style=\"list-style-type: none\">\n<ul>\n<li><a href=\"#1\">Dad discovers six-seven trend through math practice, in <i>Coeur d&#8217;Alene Press<\/i><\/a><\/li>\n<li><a href=\"#2\">The museum problem, in the <em>BBC<\/em><\/a><\/li>\n<li><a href=\"#3\">Mathematical maps, on <i>Science Friday<\/i><\/a><\/li>\n<li><a href=\"#4\">The geometry of supermoons, from the <i>Associated Press<\/i><\/a><\/li>\n<li><a href=\"#5\">Cacio e pepe calculations, in <i>Scientific American<\/i><\/a><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<hr \/>\n<h3><a id=\"1\" href=\"https:\/\/cdapress.com\/news\/2025\/oct\/11\/the-exhausted-dad-math-unlocks-popular-kid-trends\/\">The Exhausted Dad: Math unlocks popular kid trends<\/a><\/h3>\n<p><em>Coeur d&#8217;Alene Press<\/em>, October 11, 2025<\/p>\n<p>In this article from <em>Coeur d&#8217;Alene Press<\/em>, a father turns a new trend into an at-home lesson. \u201cI only just discovered THE popular phrase of the elementary and middle school crowd in 2025,\u201d Tyler Wilson writes. \u201cFans of numerology probably already know what I&#8217;m talking about, as does anyone currently living with children between the ages of 6 and 16.\u201d Wilson crafted word problems to test his kids\u2019 math skills, and the surprise answer delighted them.<\/p>\n<p><strong>Classroom Activities:<\/strong><em> six, seven, statistics<\/em><\/p>\n<ul>\n<li style=\"list-style-type: none\">\n<ul>\n<li style=\"list-style-type: none\">\n<ul>\n<li>(All levels) The number 6 is known as a \u201cperfect number\u201d because the sum of all its divisors equals itself (1 + 2 + 3 = 6). Find the next perfect number by writing out the divisors of each number between 7 and 30.<\/li>\n<li>(Mid-level) Suppose you have 7 candies, each a different color. How many different sets of 6 candies can you make? How many if all the candies are the same color? (See our <a href=\"https:\/\/mathvoices.ams.org\/mathmedia\/math-digests-may-2025\/\">May digest about counting Skittle packs<\/a> for more on this.)<\/li>\n<li>(Mid-level) How many whole numbers between 0 and 100 contain at least one 6 and one 7?\n<ul>\n<li>How many between 0 and 1 million?<\/li>\n<li>(High level) How many of these numbers are prime?<\/li>\n<\/ul>\n<\/li>\n<li>(All levels) Choose any number you want. Write a word problem based on the topics you are currently learning in math that results in that number.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p style=\"text-align: right\"><em>\u2014Max Levy<\/em><\/p>\n<hr \/>\n<h3><a id=\"2\" href=\"https:\/\/www.bbc.com\/future\/article\/20251030-louvre-robbery-the-50-year-old-maths-problem-that-can-boost-museum-security\">Louvre robbery: Could a 50-year-old maths problem have kept the museum safe?<\/a><\/h3>\n<p><em>BBC<\/em>, October 30, 2025<\/p>\n<p>On October 19, the Louvre museum was robbed of historical jewelry worth hundreds of millions. For mathematician and writer Kit Yates, the incident brought to mind an old problem about how many security cameras are needed to surveil a polygon-shaped museum gallery. The answer is simple: Count up the number of corners in the room, and divide by 3. If only preventing burglary in the real world were so easy.<\/p>\n<p><strong>Classroom Activities: <\/strong><em>graphs, geometry<\/em><\/p>\n<ul>\n<li style=\"list-style-type: none\">\n<ul>\n<li style=\"list-style-type: none\">\n<ul>\n<li>(Mid-level) Read the article, and examine the 3-coloring of Yates\u2019 15-sided gallery. Imagine placing a security camera at each of the <strong>red<\/strong> spots. Number the cameras from 1 to 4. In each triangular zone, write the number of the security camera that surveils it. Does Fisk\u2019s solution work?<\/li>\n<li>(Mid-level) For each of the following polygons, use Fisk\u2019s strategy to find an arrangement that surveils the entire shape with as few security cameras as possible.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<figure id=\"attachment_4056\" aria-describedby=\"caption-attachment-4056\" style=\"width: 641px\" class=\"wp-caption aligncenter\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" class=\"wp-image-4056 size-full\" src=\"https:\/\/i0.wp.com\/mathvoices.ams.org\/mathmedia\/wp-content\/uploads\/sites\/3\/2025\/12\/Polygons-Digests-Oct-2025-e1764715141544.png?resize=641%2C358&#038;ssl=1\" alt=\"Left: A quadrilateral. Middle: A non-convex pentagon. It looks like a rectangle with a triangular slice cut out of the top. Right: A non-convex 10-gon.\" width=\"641\" height=\"358\" srcset=\"https:\/\/i0.wp.com\/mathvoices.ams.org\/mathmedia\/wp-content\/uploads\/sites\/3\/2025\/12\/Polygons-Digests-Oct-2025-e1764715141544.png?w=641&amp;ssl=1 641w, https:\/\/i0.wp.com\/mathvoices.ams.org\/mathmedia\/wp-content\/uploads\/sites\/3\/2025\/12\/Polygons-Digests-Oct-2025-e1764715141544.png?resize=300%2C168&amp;ssl=1 300w, https:\/\/i0.wp.com\/mathvoices.ams.org\/mathmedia\/wp-content\/uploads\/sites\/3\/2025\/12\/Polygons-Digests-Oct-2025-e1764715141544.png?resize=465%2C260&amp;ssl=1 465w\" sizes=\"auto, (max-width: 641px) 100vw, 641px\" \/><figcaption id=\"caption-attachment-4056\" class=\"wp-caption-text\">Image credit: Leila Sloman.<\/figcaption><\/figure>\n<ul>\n<li style=\"list-style-type: none\">\n<ul>\n<li style=\"list-style-type: none\">\n<ul>\n<li>(All levels) Modify the problem to make it more realistic.\n<ul>\n<li>(Mid-level) With your modifications, do you think Fisk\u2019s strategy will still work? Why or why not?<\/li>\n<\/ul>\n<\/li>\n<li>(High level) In real life, galleries are three-dimensional. Can you generalize Fisk\u2019s strategy to a 3D space? (Assume cameras can surveil in all directions.) Is the 2D or 3D problem more applicable to a real museum?<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p style=\"text-align: right\"><em>\u2014Leila Sloman<\/em><\/p>\n<hr \/>\n<h3><a id=\"3\" href=\"https:\/\/www.wnycstudios.org\/podcasts\/science-friday\/articles\/how-math-helps-us-map-the-world\">How Math Helps Us Map The World<\/a><\/h3>\n<p><em>Science Friday<\/em>, October 16, 2025<\/p>\n<p>No map is perfect. Mapmakers who include many helpful details risk information overload, while keeping faithful to geography can make a map unreadable. But perhaps the most fundamental problem is mathematical: The Earth is round, while our maps are flat. In this <em>Science Friday<\/em> segment, Paulina Rowinska explains the consequences of this mismatch, and some of the other ways mathematics comes up in mapmaking.<\/p>\n<p><strong>Classroom Activities: <\/strong><em>geometry, curvature<\/em><\/p>\n<ul>\n<li style=\"list-style-type: none\">\n<ul>\n<li style=\"list-style-type: none\">\n<ul>\n<li>Listen to the segment up until timestamp 05:50. Explain in your own words:\n<ul>\n<li>(All levels) why it\u2019s not possible to draw a flat map of the Earth with no distortion,<\/li>\n<li>(All levels) what the Mercator projection is,<\/li>\n<li>(Mid-level) which features of the Mercator projection map are accurate, and which are not,<\/li>\n<li>(Mid-level) why Mercator designed the projection the way he did.<\/li>\n<\/ul>\n<\/li>\n<li>(All levels) Which of the following shapes have the same curvature as a sheet of paper? Explain your answer.\n<ul>\n<li>cylinder,<\/li>\n<li>cone,<\/li>\n<li>football,<\/li>\n<li>tennis ball.<\/li>\n<\/ul>\n<\/li>\n<li>(High level, Linear Algebra) You can calculate Gaussian curvature using a matrix called the <a href=\"https:\/\/booksite.elsevier.com\/samplechapters\/9780120887354\/9780120887354.PDF\"><strong>shape operator<\/strong><\/a>. The Gaussian curvature for a shape is the determinant of that shape\u2019s shape operator. Calculate the Gaussian curvature for the following shape operators. Do the results match your answers from the previous activity? Why do you think some shape operators change from point to point, while others don\u2019t?\n<ul>\n<li>sphere of radius $r$,$$S = \\begin{bmatrix} \u20131\/r &amp; 0 \\\\ 0 &amp; \u20131\/r \\end{bmatrix}$$<\/li>\n<li>a cylinder of radius 1,$$S = \\begin{bmatrix} 0 &amp; 0 \\\\ 0 &amp; \u20131 \\end{bmatrix}$$<\/li>\n<li>the ellipsoid$\\frac{x^2}{2} + y^2 + \\frac{z^3}{3} = 1$ at the point $(1,0,\\sqrt{\\frac{3}{2}})$,$$S = \\begin{bmatrix} 2\\sqrt{\\frac{3}{5}} &amp; 0 \\\\ 0 &amp; \\frac{2}{5}\\sqrt{\\frac{3}{5}} \\end{bmatrix}$$<\/li>\n<li>the cone $x^2 + y^2 = (1 \u2013 z)^2$ at the point $(1\/2,0,1\/2)$,$$S=\\begin{bmatrix} 0 &amp; 0 \\\\ 0 &amp; -\\frac{2}{\\sqrt{2}}\\end{bmatrix}$$<\/li>\n<li>Based on the shape operator for a sphere, calculate the curvature of Earth.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p style=\"text-align: right\"><em>\u2014Leila Sloman<\/em><\/p>\n<hr \/>\n<h3><a id=\"4\" href=\"https:\/\/apnews.com\/article\/supermoon-october-2025-108f41b4fbd04335038c721b387aa6e1\">The first supermoon of the year is approaching. Here&#8217;s what to know<\/a><\/h3>\n<p><em>Associated Press<\/em>, October 5, 2025<\/p>\n<p>On October 7, we saw the first of 2025\u2019s three supermoons. Supermoons are a type of full moon that occurs when the Earth and the Moon are relatively close in their orbits. These events appear \u201cup to 14% bigger and 30% brighter than the faintest moon of the year,\u201d writes Adithi Ramakrishnan for <em>AP News<\/em>. Another supermoon event occurred on November 4, and a third will occur on December 5.<\/p>\n<p><strong>Classroom Activities:<\/strong><em> geometry, trigonometry, astronomy<\/em><\/p>\n<ul>\n<li style=\"list-style-type: none\">\n<ul>\n<li style=\"list-style-type: none\">\n<ul>\n<li>(Mid-level) Supermoons can appear 14% larger in diameter than the full moons that are the most distant.\n<ul>\n<li>Calculate the percent difference in area and circumference between both types of full moon.<\/li>\n<li>Based on your calculations, why do you think the supermoon appears 30% brighter than a faint full moon? (Hint: refer to <a href=\"https:\/\/homepage.physics.uiowa.edu\/~pkaaret\/s09\/L10_stars.pdf\">this resource<\/a> for more information on apparent brightness, or \u201cflux.\u201d)<\/li>\n<li>If the moon\u2019s diameter appears 14% larger, does that mean it is 14% closer? Show your work.<\/li>\n<\/ul>\n<\/li>\n<li>(Mid-level) In a total solar eclipse, the Moon passes between Earth and the Sun, briefly blocking out sunlight in its entirety.\n<ul>\n<li>If the Sun is actually 400 times larger than the Moon, then what can you conclude about the relative distance from Earth to the Moon compared to the distance from Earth to the Sun? Show your work.<\/li>\n<li>What percent of the Sun\u2019s area is blocked by the moon at the moment that the edge of the moon reaches the Sun\u2019s center point in the sky?<\/li>\n<\/ul>\n<\/li>\n<li>(Mid-level) A lunar eclipse occurs when Earth casts a shadow over the moon. Assume that Earth\u2019s shadow on the moon has a radius about 2.5 times larger than the radius of the moon. Use <a href=\"https:\/\/www.omnicalculator.com\/math\/crescent-area\">this resource and calculator<\/a> to calculate the \u201ccenter distance\u201d when the Moon is 25%, 50%, and 75% illuminated.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p style=\"text-align: right\"><em>\u2014Max Levy<\/em><\/p>\n<hr \/>\n<h3><a id=\"5\" href=\"https:\/\/www.youtube.com\/shorts\/QZBF7vgYl5A\">The physics of cacio e pepe<\/a><\/h3>\n<p><em>Scientific American<\/em>, October 3, 2025<\/p>\n<p>The secret to a perfect recipe is often ratios. Cacio e pepe is proof of that in pasta form. Cacio e pepe is a creamy Italian dish made with hard cheese and black pepper. The dish\u2019s creaminess comes from an emulsion of melted cheese and starchy pasta water. \u201cCacio e pepe is a deceptively difficult dish,\u201d according to <em>Scientific American. <\/em>Physicists recently investigated the science behind why the simple ingredients are so difficult to combine in the right way.<\/p>\n<p><strong>Classroom Activities:<\/strong><em> recipes, ratios, proportions<\/em><\/p>\n<ul>\n<li style=\"list-style-type: none\">\n<ul>\n<li style=\"list-style-type: none\">\n<ul>\n<li>(All levels) The physicists conclude that to make a more foolproof cacio e pepe, you can add a small amount of corn starch. According to the <a href=\"https:\/\/pubs.aip.org\/aip\/pof\/article\/37\/4\/044122\/3345324\/Phase-behavior-of-Cacio-e-Pepe-sauce\">scientific paper<\/a>, the ideal recipe of pasta, cheese, water, and corn starch is: 300 grams, 200 grams, 150 grams, 5 grams. Calculate the following ratios:\n<ul>\n<li>Pasta to cheese<\/li>\n<li>Water to cheese<\/li>\n<li>Cheese to water<\/li>\n<li>Corn starch to water<\/li>\n<li>Corn starch to pasta<\/li>\n<\/ul>\n<\/li>\n<li>(All levels) If 300 grams of pasta is just enough for two people, calculate the required amounts of pasta, cheese, water, and corn starch for:\n<ul>\n<li>1 person<\/li>\n<li>5 people<\/li>\n<li>10 people<\/li>\n<\/ul>\n<\/li>\n<li>(Mid-level) Based on the video, describe in your words what happens if a cook uses:\n<ul>\n<li>Too much pasta water<\/li>\n<li>Too much cheese<\/li>\n<li>No pasta water<\/li>\n<li>Not enough heat<\/li>\n<li>(Hint: refer to Figures 1, 2, and 3 in <a href=\"https:\/\/pubs.aip.org\/aip\/pof\/article\/37\/4\/044122\/3345324\/Phase-behavior-of-Cacio-e-Pepe-sauce\">the scientific paper<\/a>.)<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p style=\"text-align: right\"><em>\u2014Max Levy<\/em><\/p>\n<hr \/>\n<h3>More of this month\u2019s math headlines<\/h3>\n<ul>\n<li style=\"list-style-type: none\">\n<ul>\n<li><a href=\"https:\/\/www.scientificamerican.com\/article\/mathematicians-make-surprising-breakthrough-in-3d-geometry-with-noperthedron\/\">This New Shape Breaks an \u2018Unbreakable\u2019 3D Geometry Rule<\/a><br \/>\n<em>Scientific American<\/em>, October 28, 2025<\/li>\n<li><a href=\"https:\/\/www.thejournal.ie\/maths-week-saturday-friday-answers-6847065-Oct2025\/\">Maths Week: Your Saturday puzzle<\/a><br \/>\n<em>The Journal<\/em>, October 18, 2025<\/li>\n<li><a href=\"https:\/\/www.wgbh.org\/news\/local\/2025-10-17\/the-genius-next-door-lauren-k-williams-work-uncovers-connections-between-math-and-nature\">The Genius Next Door: Lauren K. Williams\u2019 work uncovers connections between math and nature<\/a><br \/>\nWGBH <em>Under the Radar with Callie Crossley<\/em>, October 17, 2025<\/li>\n<li><a href=\"https:\/\/www.quantamagazine.org\/the-hidden-math-of-ocean-waves-crashes-into-view-20251015\/\">The Hidden Math of Ocean Waves Crashes Into View<\/a><br \/>\n<em>Quanta Magazine<\/em>, October 15, 2025<\/li>\n<li><a href=\"https:\/\/connectsci.au\/news\/news-parent\/3508\/The-maths-of-how-stalagmites-form?searchresult=1\">The maths of how stalagmites form<\/a><br \/>\n<em>ConnectSci News<\/em>, October 14, 2025<\/li>\n<li><a href=\"https:\/\/www.scientificamerican.com\/article\/how-the-math-that-powers-google-foresaw-the-new-pope\/\">The Math That Predicted the New Pope<\/a><br \/>\n<em>Scientific American<\/em>, October 11, 2025<\/li>\n<li><a href=\"https:\/\/www.nytimes.com\/2025\/10\/10\/science\/mathematics-art-roelofs.html\">Every Artist Has a Favorite Subject. For Some, That\u2019s Math.<\/a><br \/>\n<em>The New York Times<\/em>, October 10, 2025<\/li>\n<li><a href=\"https:\/\/www.quantamagazine.org\/origami-patterns-solve-a-major-physics-riddle-20251006\/\">Origami Patterns Solve a Major Physics Riddle<\/a><br \/>\n<em>Quanta Magazine<\/em>, October 6, 2025<\/li>\n<li><a href=\"https:\/\/www.jpost.com\/consumerism\/article-869179\">&#8220;Trust numbers, Not intuition&#8221;: Andrew Shepard on data-driven roulette analysis<\/a><br \/>\n<em>The Jerusalem Post<\/em>, October 5, 2025<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>October digests: Dad discovers six-seven trend through math practice, in Coeur d&#8217;Alene Press The museum problem, in the BBC Mathematical maps, on Science Friday The geometry of supermoons, from the Associated Press Cacio e pepe calculations, in Scientific American The Exhausted Dad: Math unlocks popular kid trends Coeur d&#8217;Alene Press,<span class=\"more-link\"><a href=\"https:\/\/mathvoices.ams.org\/mathmedia\/math-digests-october-2025\/\">Read More &rarr;<\/a><\/span><\/p>\n","protected":false},"author":13,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[2],"tags":[204,216,35,260,498,113,497,496,495,494,84,142],"class_list":["entry","author-leilasloman","post-4055","post","type-post","status-publish","format-standard","category-math-in-the-media-digests","tag-astronomy","tag-curvature","tag-geometry","tag-graphs","tag-proportions","tag-ratios","tag-recipes","tag-seven","tag-six","tag-six-seven","tag-statistics","tag-trigonometry"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_likes_enabled":true,"_links":{"self":[{"href":"https:\/\/mathvoices.ams.org\/mathmedia\/wp-json\/wp\/v2\/posts\/4055","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mathvoices.ams.org\/mathmedia\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mathvoices.ams.org\/mathmedia\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mathvoices.ams.org\/mathmedia\/wp-json\/wp\/v2\/users\/13"}],"replies":[{"embeddable":true,"href":"https:\/\/mathvoices.ams.org\/mathmedia\/wp-json\/wp\/v2\/comments?post=4055"}],"version-history":[{"count":4,"href":"https:\/\/mathvoices.ams.org\/mathmedia\/wp-json\/wp\/v2\/posts\/4055\/revisions"}],"predecessor-version":[{"id":4060,"href":"https:\/\/mathvoices.ams.org\/mathmedia\/wp-json\/wp\/v2\/posts\/4055\/revisions\/4060"}],"wp:attachment":[{"href":"https:\/\/mathvoices.ams.org\/mathmedia\/wp-json\/wp\/v2\/media?parent=4055"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mathvoices.ams.org\/mathmedia\/wp-json\/wp\/v2\/categories?post=4055"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mathvoices.ams.org\/mathmedia\/wp-json\/wp\/v2\/tags?post=4055"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}