Introducing casio's most advanced scientific calculator, the casio fx 991 cw. A new and upgraded version of the casio fx 991 ex.featuring additional features, which include a high definition display and a massively improved ui.take this calculator into uk exams! This calculator is approved for key stages 3, 4 and 5 and is recommended for advanced gcse, a as level and higher.gain a better understanding of mathematical expressions on the display screen, for example roots and fractions as they appear in your textbooks, this will increase your comprehension because the results are easier to understand and in plain sight.its quick and easy to navigate user interface gives you access to more functionality, with over 540 different functions to try out, a new key layout and menus.. Recommended for advanced gcse, a as level and higher.. 540 functions to try!. 3 year guarantee.. Approximate package dimensions mm h 110 w 770 d 1620. Package weight 950g