{"product_id":"math-equations-and-notations-mathematics-chalkboard-geek-wall-clock-educational-gifts-for-kids-teachers-school-classroom-decor","title":"Blackboard math equations wall clock - THEOREMA","description":"\u003cstyle\u003e\n.aa{font-family:Georgia,'Times New Roman',serif;color:#1A1A1A;line-height:1.7;font-size:15px;max-width:760px;margin:0 auto}\n.aa p{margin:0 0 1rem}\n.aa a{color:#185FA5;text-decoration:underline}\n.aa .aa-title{display:inline-block;border-bottom:2px solid #FAC775;padding-bottom:4px;font-size:16px;font-weight:600;margin:1.75rem 0 .5rem;letter-spacing:.3px;color:#1A1A1A}\n.aa .aa-badge{display:inline-block;font-size:11px;font-weight:700;letter-spacing:.5px;text-transform:uppercase;padding:3px 10px;border-radius:20px;margin:0 4px 4px 0;vertical-align:middle;font-family:Georgia,serif}\n.aa .aa-badge-or{background:#FAC775;color:#1A1A1A}\n.aa .aa-badge-brun{background:#5C3A1E;color:#FFF9E8}\n.aa .aa-badge-noir{background:#1A1A1A;color:#FAC775}\n.aa 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summary::after{content:\"\\2212\"}\n.aa .aa-a{font-size:13px;color:#3a3a3a;margin-top:.5rem}\n.aa .aa-a p{margin:0 0 .5rem}\n@media(max-width:600px){.aa .aa-vars,.aa .aa-ben{grid-template-columns:1fr}}\n\u003c\/style\u003e\n\u003cdiv class=\"aa\"\u003e\n\n\u003cp\u003e\u003cspan class=\"aa-badge aa-badge-noir\"\u003eThe Lab\u003c\/span\u003e \u003cspan class=\"aa-badge aa-badge-bleu\"\u003eMathematics\u003c\/span\u003e Factorials, derivatives, determinants, series sums: the THEOREMA \u003cstrong\u003eblackboard wall clock\u003c\/strong\u003e is designed for those who see mathematics as a playground. Its round \u003cstrong\u003e30 cm diameter\u003c\/strong\u003e dial reproduces the look of a \u003cstrong\u003eschool chalkboard\u003c\/strong\u003e covered in calculations, with each hour replaced by a \u003cstrong\u003emathematical expression\u003c\/strong\u003e: π⁰ for 1, 2! for 2, the \u003cstrong\u003ederivative\u003c\/strong\u003e of 3x for 3, √(3²+4²) for 5, the \u003cstrong\u003edeterminant\u003c\/strong\u003e of a matrix for 8, 2×3! for 12. Two white hands stand out against this busy background, powered by a \u003cstrong\u003equartz movement\u003c\/strong\u003e. Two versions are available: with a \u003cstrong\u003eblack metal frame\u003c\/strong\u003e and acrylic glass protecting the dial for a more assertive look, or without a frame or glass for a raw, authentic blackboard feel. Hung in an office, library, classroom, or laboratory, it pays homage to the formulas once written in chalk, inviting every visitor to a small challenge: deciphering the time behind each expression.\u003c\/p\u003e\n\n\u003ch3 class=\"aa-title\"\u003eThe two versions available\u003c\/h3\u003e\n\n\u003cdiv class=\"aa-vars\"\u003e\n\n\u003cdiv class=\"aa-var\"\u003e\n\n\u003cdiv class=\"aa-var-v dark\" style=\"background: linear-gradient(135deg,#1A1A1A 0%,#3A3A3A 50%,#1A1A1A 100%);\"\u003eMETAL FRAME\u003c\/div\u003e\n\n\u003cdiv class=\"aa-var-i\"\u003e\n\n\u003cspan class=\"aa-var-n\"\u003eBlack metal frame and acrylic glass\u003c\/span\u003e\u003cspan class=\"aa-var-d\"\u003eBlack metal frame, acrylic glass over the dial: protected, assertive finish\u003c\/span\u003e\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-var\"\u003e\n\n\u003cdiv class=\"aa-var-v dark\" style=\"background: #1A1A1A;\"\u003eFRAMELESS\u003c\/div\u003e\n\n\u003cdiv class=\"aa-var-i\"\u003e\n\n\u003cspan class=\"aa-var-n\"\u003eFrameless\u003c\/span\u003e\u003cspan class=\"aa-var-d\"\u003eBare dial, no frame or glass: raw finish, blackboard style\u003c\/span\u003e\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cp\u003eThe dial, expressions, and movement are identical in both versions. The metal frame adds a clean line around the dial and includes acrylic glass to protect it from dust; the frameless version offers a direct view of the dial with no glare and a lighter profile.\u003c\/p\u003e\n\n\u003cdiv class=\"aa-mat\"\u003e\n\n\u003ch3\u003eTwelve hours, twelve mathematical concepts\u003c\/h3\u003e\n\n\u003cp\u003eEach position on the dial corresponds to a different concept. At 1 o'clock, \u003cstrong\u003eπ⁰\u003c\/strong\u003e reminds us that any non-zero number to the power of zero equals 1. At 2 o'clock, \u003cstrong\u003e2!\u003c\/strong\u003e (factorial of 2) equals 2. At 3 o'clock, the \u003cstrong\u003ederivative\u003c\/strong\u003e of 3x with respect to x equals 3. At 4 o'clock, 2²; at 5 o'clock, √(3²+4²) evokes the famous 3-4-5 right triangle and the \u003cstrong\u003ePythagorean theorem\u003c\/strong\u003e. At 6 o'clock, the sum of integers from 1 to 3 equals 6.\u003c\/p\u003e\n\n\u003cp\u003eThe rest of the dial is just as rich: 14\/2 for 7, the \u003cstrong\u003edeterminant\u003c\/strong\u003e of the matrix [3 1 ; 1 3], i.e., 3×3 − 1×1 = 8, for 8 o'clock; 3² for 9; 4+3×2, testing order of operations, for 10; √121 for 11; and finally 2×3!, or 2×6, for noon. With twelve expressions, the clock covers \u003cstrong\u003ealgebra\u003c\/strong\u003e, analysis, geometry, and linear algebra: a true \u003cstrong\u003erevision curriculum\u003c\/strong\u003e hanging on your wall.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003ch3 class=\"aa-title\"\u003eWhy you'll love it\u003c\/h3\u003e\n\n\u003cdiv class=\"aa-ben\"\u003e\n\n\u003cdiv class=\"aa-b\"\u003e\n\n\u003cspan class=\"ic\"\u003e✦\u003c\/span\u003e\n\u003cdiv\u003e\n\n\u003cspan class=\"tt\"\u003eAn educated dial\u003c\/span\u003e\u003cspan class=\"ds\"\u003eFactorials, derivatives, determinants, sums: high school and university-level expressions.\u003c\/span\u003e\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-b\"\u003e\n\n\u003cspan class=\"ic\"\u003e◆\u003c\/span\u003e\n\u003cdiv\u003e\n\n\u003cspan class=\"tt\"\u003eSchool chalkboard spirit\u003c\/span\u003e\u003cspan class=\"ds\"\u003eA black background covered in calculations reminiscent of classroom formula boards.\u003c\/span\u003e\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-b\"\u003e\n\n\u003cspan class=\"ic\"\u003e➤\u003c\/span\u003e\n\u003cdiv\u003e\n\n\u003cspan class=\"tt\"\u003eTwo versions\u003c\/span\u003e\u003cspan class=\"ds\"\u003eWith a black metal frame and acrylic glass, or frameless for a raw look.\u003c\/span\u003e\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-b\"\u003e\n\n\u003cspan class=\"ic\"\u003e✦\u003c\/span\u003e\n\u003cdiv\u003e\n\n\u003cspan class=\"tt\"\u003e30 cm format\u003c\/span\u003e\u003cspan class=\"ds\"\u003eA versatile diameter, readable in an office, library, or kitchen.\u003c\/span\u003e\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-b\"\u003e\n\n\u003cspan class=\"ic\"\u003e◆\u003c\/span\u003e\n\u003cdiv\u003e\n\n\u003cspan class=\"tt\"\u003eQuartz movement\u003c\/span\u003e\u003cspan class=\"ds\"\u003eA simple and reliable mechanism, battery-powered (battery not included).\u003c\/span\u003e\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-b\"\u003e\n\n\u003cspan class=\"ic\"\u003e➤\u003c\/span\u003e\n\u003cdiv\u003e\n\n\u003cspan class=\"tt\"\u003eA constant challenge\u003c\/span\u003e\u003cspan class=\"ds\"\u003eEvery glance becomes an opportunity to test your knowledge, or that of your guests.\u003c\/span\u003e\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-des\"\u003e\n\n\u003cp class=\"t\"\u003eThe blackboard never gets erased\u003c\/p\u003e\n\n\u003cdiv class=\"x\"\u003e\n\n\u003cp\u003eAnyone who has spent hours in front of a chalk-covered board will recognize this atmosphere: the calculations in the background, the overlapping formulas, the \u003cstrong\u003eproof\u003c\/strong\u003e progressing line by line. THEOREMA captures this moment and transforms it into an \u003cstrong\u003eeveryday object\u003c\/strong\u003e. Amidst this abundance, the twelve expressions on the dial read like so many small victories.\u003c\/p\u003e\n\n\u003cp\u003eWith its \u003cstrong\u003eblack metal\u003c\/strong\u003e frame, the clock takes on the air of a laboratory instrument; without a frame, it evokes the classroom slate directly. In either case, it appeals to minds that love to understand, to teachers who pass on knowledge, and to engineers and researchers who know that a \u003cstrong\u003ewell-written formula\u003c\/strong\u003e has its own elegance.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-steps\"\u003e\n\n\u003ch4\u003eInstalling your THEOREMA clock\u003c\/h4\u003e\n\n\u003cdiv class=\"aa-step\"\u003e\n\n\u003cspan class=\"aa-step-n\"\u003e1\u003c\/span\u003e\n\u003cdiv class=\"aa-step-c\"\u003e\n\n\u003cstrong\u003eInsert the battery\u003c\/strong\u003e (not included) into the quartz movement compartment on the back of the dial, observing the indicated polarity.\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-step\"\u003e\n\n\u003cspan class=\"aa-step-n\"\u003e2\u003c\/span\u003e\n\u003cdiv class=\"aa-step-c\"\u003e\n\n\u003cstrong\u003eSet the time\u003c\/strong\u003e using the movement's wheel, turning gently clockwise.\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-step\"\u003e\n\n\u003cspan class=\"aa-step-n\"\u003e3\u003c\/span\u003e\n\u003cdiv class=\"aa-step-c\"\u003e\n\n\u003cstrong\u003ePrepare the mounting\u003c\/strong\u003e: a nail, screw, or hook suitable for your wall, at eye level to enjoy the expressions.\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-step\"\u003e\n\n\u003cspan class=\"aa-step-n\"\u003e4\u003c\/span\u003e\n\u003cdiv class=\"aa-step-c\"\u003e\n\n\u003cstrong\u003eHang the clock\u003c\/strong\u003e and ensure it is straight by using the noon expression (2×3!) as a reference point.\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\n\u003ch3 class=\"aa-title\"\u003eTHEOREMA or black background math clock?\u003c\/h3\u003e\n\n\u003cdiv class=\"aa-cmp\"\u003e\n\n\u003ctable\u003e\n\n\u003cthead\u003e\n\n\u003ctr\u003e\n\n\u003cth\u003eCriteria\u003c\/th\u003e\n\n\u003cth\u003eTHEOREMA (this clock)\u003c\/th\u003e\n\n\u003cth\u003eBlack background math clock\u003c\/th\u003e\n\n\n\u003c\/tr\u003e\n\n\n\u003c\/thead\u003e\n\n\u003ctbody\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eDial\u003c\/td\u003e\n\n\u003ctd\u003eSchool chalkboard style, covered in calculations\u003c\/td\u003e\n\n\u003ctd\u003eSolid black background, white chalk operations\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr class=\"hl\"\u003e\n\n\u003ctd\u003eExpressions\u003c\/td\u003e\n\n\u003ctd\u003eFactorials, derivatives, determinants, sums, roots\u003c\/td\u003e\n\n\u003ctd\u003eMultiplications, roots, proportions, equations\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eLevel\u003c\/td\u003e\n\n\u003ctd\u003eHigh school, university\u003c\/td\u003e\n\n\u003ctd\u003eMental math, middle and high school\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr class=\"hl\"\u003e\n\n\u003ctd\u003eDiameter\u003c\/td\u003e\n\n\u003ctd\u003e30 cm\u003c\/td\u003e\n\n\u003ctd\u003eApprox. 25, 30, 35 or 40 cm\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eFrame\u003c\/td\u003e\n\n\u003ctd\u003eBlack metal frame and acrylic glass, or frameless\u003c\/td\u003e\n\n\u003ctd\u003eFrameless, light wood back\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr class=\"hl\"\u003e\n\n\u003ctd\u003eMaterial (supplier)\u003c\/td\u003e\n\n\u003ctd\u003eAcrylic \/ plastic\u003c\/td\u003e\n\n\u003ctd\u003eBamboo and wood\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\n\u003c\/tbody\u003e\n\n\n\u003c\/table\u003e\n\n\n\u003c\/div\u003e\n\n\u003cp\u003eThe Lab offers another mathematical clock with a solid black background and more accessible operations, available in four diameters. Find it with our other time-themed items in the \u003ca href=\"\/collections\/temps-et-meteo\"\u003etime and weather objects\u003c\/a\u003e collection.\u003c\/p\u003e\n\n\u003cdiv class=\"aa-info\"\u003e\n\n\u003cp\u003e\u003cstrong\u003eGood to know:\u003c\/strong\u003e depending on the supplier, the clock is made of \u003cstrong\u003eacrylic and plastic\u003c\/strong\u003e, with a \u003cstrong\u003e30 cm\u003c\/strong\u003e diameter. On the framed version, black metal surrounds the dial and \u003cstrong\u003eacrylic glass\u003c\/strong\u003e protects it. The battery is not included. The time is also very easy to read simply by the position of the hands, without solving the expressions.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-tip\"\u003e\n\n\u003cp\u003e\u003cstrong\u003eAdvice:\u003c\/strong\u003e the \u003cstrong\u003eframeless\u003c\/strong\u003e version avoids reflections from a window or lamp on the dial; the \u003cstrong\u003eframed\u003c\/strong\u003e version protects the dial from dust and is well-suited for kitchens and high-traffic areas. For a brightly lit office, opt for the frameless version.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003ch3 class=\"aa-title\"\u003eTechnical specifications\u003c\/h3\u003e\n\n\u003cdiv class=\"aa-sp\"\u003e\n\n\u003ctable\u003e\n\n\u003ctbody\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eType\u003c\/td\u003e\n\n\u003ctd\u003eRound wall clock with mathematical dial\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eDial\u003c\/td\u003e\n\n\u003ctd\u003eBlack, school chalkboard aspect covered in calculations\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eHour indications\u003c\/td\u003e\n\n\u003ctd\u003eMathematical expressions (π⁰, 2!, d\/dx 3x, √(3²+4²), determinant…)\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eHands\u003c\/td\u003e\n\n\u003ctd\u003eWhite\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eDiameter\u003c\/td\u003e\n\n\u003ctd\u003e30 cm\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eMetal frame version\u003c\/td\u003e\n\n\u003ctd\u003eBlack metal frame and acrylic glass\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eFrameless version\u003c\/td\u003e\n\n\u003ctd\u003eDial without frame or glass\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eMaterial (supplier)\u003c\/td\u003e\n\n\u003ctd\u003eAcrylic \/ plastic\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eMovement\u003c\/td\u003e\n\n\u003ctd\u003eQuartz\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003ePower source\u003c\/td\u003e\n\n\u003ctd\u003eBattery (not included; type not specified)\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eMounting\u003c\/td\u003e\n\n\u003ctd\u003eWall\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd\u003eWeight\u003c\/td\u003e\n\n\u003ctd\u003eNot specified\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\n\u003c\/tbody\u003e\n\n\n\u003c\/table\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-warn\"\u003e\n\n\u003cp\u003e\u003cstrong\u003ePrecautions:\u003c\/strong\u003e keep the battery out of reach of children: if swallowed, consult a doctor immediately. Remove the battery if not in use for a long period and dispose of it at an appropriate collection point. Attach the clock to a support suitable for the wall type. Clean the dial or acrylic glass with a soft, dry cloth; do not use abrasive products or solvents, which could scratch or dull the surface.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"aa-gift\"\u003e\n\n\u003ch3\u003eA gift for scientific minds\u003c\/h3\u003e\n\n\u003cp\u003eTHEOREMA is the \u003cstrong\u003eideal gift for a mathematics or physics teacher\u003c\/strong\u003e, a preparatory class student, an engineer, or a researcher. It celebrates a high school diploma, graduation, retirement, or setting up a new office.\u003c\/p\u003e\n\n\u003cp\u003eTo complete this gift, discover \u003ca href=\"\/collections\/objets-scientifiques\"\u003eThe Lab's scientific objects\u003c\/a\u003e or our \u003ca href=\"\/collections\/casse-tetes-et-bureau\"\u003epuzzles and office objects\u003c\/a\u003e.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003ch3 class=\"aa-title\"\u003eFrequently asked questions\u003c\/h3\u003e\n\n\u003cdiv class=\"aa-faq\"\u003e\n\n\u003cdetails class=\"aa-q\"\u003e\n\u003csummary\u003eWhich expressions appear on the dial?\u003c\/summary\u003e\n\u003cdiv class=\"aa-a\"\u003e\n\n\u003cp\u003eEach hour is represented by a \u003cstrong\u003emathematical expression\u003c\/strong\u003e: π⁰ for 1, 2! for 2, the derivative of 3x for 3, 2² for 4, √(3²+4²) for 5, the sum of integers from 1 to 3 for 6, 14\/2 for 7, the \u003cstrong\u003edeterminant\u003c\/strong\u003e of the matrix [3 1 ; 1 3] for 8, 3² for 9, 4+3×2 for 10, √121 for 11, and 2×3! for 12. These expressions span several fields: powers, \u003cstrong\u003efactorials\u003c\/strong\u003e, analysis, geometry, sums, and linear algebra. The background of the dial is also covered in decorative calculations, which enhance the blackboard effect without interfering with reading the hours and hands.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003c\/details\u003e\n\u003cdetails class=\"aa-q\"\u003e\n\u003csummary\u003eDo you have to be a mathematician to read the time?\u003c\/summary\u003e\n\u003cdiv class=\"aa-a\"\u003e\n\n\u003cp\u003eNot at all. The hands work like on any clock: the short one points to the hours, the long one to the minutes, and their \u003cstrong\u003eposition\u003c\/strong\u003e is enough to read the time, exactly like on a dial without numbers. The mathematical expressions are an \u003cstrong\u003eoptional game\u003c\/strong\u003e: the curious will enjoy checking each result, while others will simply enjoy the aesthetics of the blackboard. Some expressions are accessible to everyone, like 14\/2 or 3²; others, like the derivative or the determinant, will draw on memories of \u003cstrong\u003ehigh school or university studies\u003c\/strong\u003e, and can spark lively discussions with your guests.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003c\/details\u003e\n\u003cdetails class=\"aa-q\"\u003e\n\u003csummary\u003eWhat is the difference between the framed and frameless versions?\u003c\/summary\u003e\n\u003cdiv class=\"aa-a\"\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eframed\u003c\/strong\u003e version is surrounded by a \u003cstrong\u003eblack metal\u003c\/strong\u003e circle and features \u003cstrong\u003eacrylic glass\u003c\/strong\u003e in front of the dial. It offers a more assertive profile, close to an office or laboratory clock, and protects the dial from dust and fingerprints. The \u003cstrong\u003eframeless\u003c\/strong\u003e version presents the bare dial without glass: its rendering is rawer, very close to a classroom slate, and it produces no reflections, even facing a window. The 30 cm diameter, dial, hands, and quartz movement are identical in both versions: the choice depends on your interior decor and the room's lighting.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003c\/details\u003e\n\u003cdetails class=\"aa-q\"\u003e\n\u003csummary\u003eWhat battery should be used, and is it provided?\u003c\/summary\u003e\n\u003cdiv class=\"aa-a\"\u003e\n\n\u003cp\u003eThe clock runs on a \u003cstrong\u003equartz movement\u003c\/strong\u003e powered by a battery. The battery \u003cstrong\u003eis not included\u003c\/strong\u003e: remember to provide one before installation, especially if giving it as a gift. The exact type of battery was not provided to us by our supplier; movements of this format generally run on an \u003cstrong\u003eAA\u003c\/strong\u003e battery, but we invite you to check the compartment on the back of the clock upon receipt. Insert the battery observing the indicated polarity, then set the time using the wheel. When the clock starts lagging or stops, simply replace the battery.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003c\/details\u003e\n\u003cdetails class=\"aa-q\"\u003e\n\u003csummary\u003eWhat is the difference from The Lab's other math clock?\u003c\/summary\u003e\n\u003cdiv class=\"aa-a\"\u003e\n\n\u003cp\u003eThe Lab offers two complementary mathematical clocks. THEOREMA features a \u003cstrong\u003eschool chalkboard\u003c\/strong\u003e-style dial entirely covered in calculations, with \u003cstrong\u003ehigh school and university-level\u003c\/strong\u003e expressions: factorials, derivatives, determinants, sums. It measures 30 cm and comes with a metal frame and acrylic glass or frameless. The other model features a \u003cstrong\u003esolid black background\u003c\/strong\u003e against which more accessible mental math operations stand out, such as multiplications, square roots, and simple equations; it is offered in four diameters, from approximately 25 to 40 cm, with a light wood back. THEOREMA is the more scholarly of the two.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003c\/details\u003e\n\u003cdetails class=\"aa-q\"\u003e\n\u003csummary\u003eHow do I maintain the clock?\u003c\/summary\u003e\n\u003cdiv class=\"aa-a\"\u003e\n\n\u003cp\u003eVery simple maintenance is sufficient. For the \u003cstrong\u003eframed\u003c\/strong\u003e version, dust the acrylic glass and metal frame with a \u003cstrong\u003esoft, dry cloth\u003c\/strong\u003e, or a slightly damp microfiber cloth for fingerprints. Avoid abrasive products, alcohol, and solvents, which could scratch or dull the acrylic. For the \u003cstrong\u003eframeless\u003c\/strong\u003e version, as the dial is exposed, use only a soft, dry cloth without rubbing hard, in order to preserve the calculation print. In all cases, avoid installation in a very humid room or in direct sunlight, which could alter the dial's colors over time.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003c\/details\u003e\n\u003cdetails class=\"aa-q\"\u003e\n\u003csummary\u003eIs this clock silent?\u003c\/summary\u003e\n\u003cdiv class=\"aa-a\"\u003e\n\n\u003cp\u003eThe clock is equipped with a \u003cstrong\u003equartz movement\u003c\/strong\u003e, but our supplier does not specify if it is a \u003cstrong\u003econtinuous sweep\u003c\/strong\u003e movement, known to be silent, or a classic ticking movement. We therefore prefer not to promise completely silent operation. For a bedroom or a room where the slightest noise matters, the other math clock from The Lab, whose movement is described as \u003cstrong\u003esilent\u003c\/strong\u003e by the manufacturer, may be an alternative to consider. For an office, library, kitchen, or classroom, the noise issue is generally secondary, and THEOREMA fits perfectly.\u003c\/p\u003e\n\n\n\u003c\/div\u003e\n\n\u003c\/details\u003e\n\n\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"Atelier Atypique","offers":[{"title":"Unframed","offer_id":54860805669187,"sku":"32973356660-No Frame-CHINA","price":65.0,"currency_code":"USD","in_stock":true},{"title":"Black metal frame and acrylic glass","offer_id":54860805636419,"sku":"32973356660-Metal Frame-CHINA","price":93.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0231\/3365\/0991\/files\/S059dcd9a559044f8beedbf4ff182a9cas.webp?v=1791060611","url":"https:\/\/atelier-atypique.com\/products\/math-equations-and-notations-mathematics-chalkboard-geek-wall-clock-educational-gifts-for-kids-teachers-school-classroom-decor","provider":"Atelier Atypique","version":"1.0","type":"link"}