Texas Instruments graphing calculators have helped many a student with algebra, pre-calculus and upside-down anatomical slang. Now, the company is back with an upgrade for the modern world, the TI-84 Evo . The new device lets you get your math on with a faster processor, a new icon-based home screen and a redesigned keypad. TI is marketing it as something akin to the Light Phone of calculators. Unlike calculator apps on phones or computers, the "distraction-free" TI-84 Evo is a single-purpose device "designed to do one thing exceptionally well — math." Without notifications, social media apps or even Wi-Fi, there's less to draw your focus away from the math problems at hand. (However, there will always be the sidesplittingly funny "58008" to relieve your boredom.) Texas Instruments The new model's processor is three times faster than its predecessor. It also adds 50 percent more graphing space, a simplified keypad and USB-C charging.…