The Genie 510 BK and 840 BK models are handy, high-quality calculators for the office, school and everyday use. The Genie 510 BK is a compact pocket calculator with an 8-digit display in a flat, elegant design. An easy-to-clean plastic keyboard ensures comfortable typing, the dual-power supply automatically switches to solar when there is sufficient light and seamlessly switches to battery (included) in low light. It is capable of basic arithmetic operations, percentage and root calculation (√), has a sign key (+/-), a 3-key memory (M+/M-/MRC) and CE for correcting the last entry. The Genie 840 BK is designed as a compact desktop calculator and offers a large, angled 10-digit display for optimum readability. Here too, non-slip plastic keys and dual power are used and the battery is included in the scope of delivery. In addition to the basic arithmetic operations, percent and root (√), the 840 BK offers a 4-key memory (M+/M-/MR/MC). Both calculators combine reliable calculation functions with a clear appearance and robust suitability for everyday use.