--- product_id: 653538830 title: "DUPOTA OA-991EX Scientific Calculator 552 Functions 2-Line Written Display | Support Fraction and Decimal Point Conversion Solar Battery, Ideal for Middle High School Students and Teachers" brand: "dupota" price: "$35.48" currency: USD in_stock: true category: "Dupota" url: https://www.desertcart.us/products/653538830-dupota-oa-991ex-scientific-calculator-552-functions-2-line-written store_origin: US region: United States of America --- # Quad-core processor for lightning-fast calculations 552 versatile scientific functions Dual solar & battery power for nonstop use DUPOTA OA-991EX Scientific Calculator 552 Functions 2-Line Written Display | Support Fraction and Decimal Point Conversion Solar Battery, Ideal for Middle High School Students and Teachers **Brand:** dupota **Price:** $35.48 **Availability:** ✅ In Stock ## Summary > ⚡ Elevate your calculations—because precision waits for no one! ## Quick Answers - **What is this?** DUPOTA OA-991EX Scientific Calculator 552 Functions 2-Line Written Display | Support Fraction and Decimal Point Conversion Solar Battery, Ideal for Middle High School Students and Teachers by dupota - **How much does it cost?** $35.48 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/653538830-dupota-oa-991ex-scientific-calculator-552-functions-2-line-written) ## Best For - dupota enthusiasts ## Why This Product - Trusted dupota brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Ultra-Light & Ergonomic Design:** Carry it anywhere with confidence—anti-slip keys and a durable sliding cover built for intense study sessions. - • **Blazing Fast Quad-Core Processor:** Solve high-order equations and matrix operations in a flash. - • **Crystal-Clear 2-Line Natural Display:** See formulas and results simultaneously with adjustable contrast for eye comfort. - • **Master Complex Calculations with 552 Functions:** From algebra to integration, handle any equation like a pro. - • **Dual Power System for Uninterrupted Performance:** Solar plus battery ensures your calculator never quits mid-exam. ## Overview The OA-991EX Scientific Calculator combines 552 advanced functions with a high-resolution 2-line natural display and a quad-core processor for rapid, precise calculations. Its dual solar and battery power system guarantees long-lasting use, while the lightweight, durable design with anti-slip keys makes it perfect for students and teachers tackling complex math and science challenges. ## Description desertcart.com : DUPOTA OA-991EX Scientific Calculator 552 Functions 2-Line Written Display | Support Fraction and Decimal Point Conversion Solar Battery, Ideal for Middle High School Students and Teachers : Office Products ## Features - 【552 Calculation Functions】Scientific calculators 991ex features 552 functions, including spreadsheet, exponential, matrix calculation, statistics, integration, algebra, complex number calculation, standard deviation, and more, suitable for handling complex equations and statistical data. From beginner to advanced courses, its practicality can meet the needs of various digital fields. - 【High Resolution & Multi-line Display】991ex scientific calculator is equipped with a high-resolution multi-line display that supports natural display of mathematical formulas and fractions, presenting expressions intuitively and showing the calculation process and results simultaneously. Adjust the screen contrast according to your preference for a clear and comfortable experience. - 【High-Efficiency Calculator】Scientific calculators has an integrated spreadsheet mode that supports data input and formula calculation; advanced operations such as 4×4 matrix and vector operations, with a quad-core processor to enhance calculation speed, making it faster to solve high-order equations and perform matrix operations, meeting the needs of efficient calculation. - 【Long Battery Life & Durable】Fraction calculator has a dual power system of solar and button battery for long-lasting operation. It automatically shuts down after 8 minutes of inactivity. Sliding back cover protects the calculator body, making it pressure-resistant and durable, meeting the needs of high-intensity study and outdoor use, providing peace of mind in exam scenarios. - 【Ultra-light & Portable】Advanced scientific calculators is designed to be lightweight (about 125g), suitable for carrying around. The button layout is clear, and the anti-slip material enhances the operation feel. It has various function keys to simplify complex calculations, including a "CHG" button for switching between fractions and decimals, making precise value calculations easy. ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B0D9Q6RK43 | | Best Sellers Rank | #345,605 in Office Products ( See Top 100 in Office Products ) #239 in Scientific Calculators | | Brand | DUPOTA | | Calculator Type | Engineering/Scientific | | Color | black | | Customer Reviews | 4.2 4.2 out of 5 stars (40) | | Display Type | LCD | | Enclosure Material | Plastic | | Item Dimensions L x W | 6.5"L x 3.15"W | | Item Weight | 125 g | | Manufacturer | DUPOTA | | Mfr Part Number | OA-991EX PLUS-XY | | Model Name | OA-991EX PLUS | | Model Number | OA-991EX PLUS | | Number of Batteries | 1 LR44 batteries required. (included) | | Number of Items | 1 | | Power Source | Solar Powered | | Screen Size | 2.5 inches | | UPC | 726434206879 | ## Product Details - **Brand:** DUPOTA - **Calculator Type:** Engineering/Scientific - **Color:** black - **Power Source:** Solar Powered - **Screen Size:** 2.5 inches ## Images ![DUPOTA OA-991EX Scientific Calculator 552 Functions 2-Line Written Display | Support Fraction and Decimal Point Conversion Solar Battery, Ideal for Middle High School Students and Teachers - Image 1](https://m.media-amazon.com/images/I/71edBbg+O4L.jpg) ## Available Options This product comes in different **Size** options. ## Frequently Bought Together - DUPOTA OA-991EX Plus Scientific Calculator 552 Functions 2-Line 10+2 Digits Written Display Solar Battery - Ideal for Middle High School Students and Teachers, Black - Desk Calculator 12 Digit Extra Large LCD Display, Touch Comfortable with Big Buttons, PXY Two Way Power Battery and Solar Standard Function Office Calculators - Desktop Calculator Extra Large 5in LCD Display 12-Digit Big Button Giant Accounting Calculator, Battery & Solar Powered, for Office Business & Home(OS-6815) --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.us/products/653538830-dupota-oa-991ex-scientific-calculator-552-functions-2-line-written](https://www.desertcart.us/products/653538830-dupota-oa-991ex-scientific-calculator-552-functions-2-line-written) --- *Product available on Desertcart United States of America* *Store origin: US* *Last updated: 2026-08-14*