The CATIGA CS-183 Scientific Calculator is a robustly designed calculator with systems capable of supporting heavy use. Its simple user interface and button layout make work a breeze for even the more inexperienced user. Yet with 200 functions including percentages, trigonometry, 24 parentheses levels, summation, regressions, fractions, regressions, and permutations/combinatorics it is appropriate for any academic or business environment. Its dual-use LCD screen promotes accuracy and promotes easy correction of work.