What is Calculator?
[[Image:Schoty abacus.jpg|thumb|upright|An [[abacus]] is a simple calculator.]] [[File:Machine à calculer comptable (Liège).jpg|thumb|upright|Mechanical calculator, early 20th century]] A '''calculator''' is a machine which allows people to do [[mathematics|math]] operations more easily. For example, most calculators will [[addition|add]], [[subtraction|subtract]], [[multiplication|multiply]], and [[Division (mathematics)|divide]]. Some also do [[square root]]s, and more complex calculators can help with [[calculus]] and draw function graphs. Calculators are found everywhere. A [[smartphone]] or other [[computer]] can also act as a calculator. Some calculators, like the [[abacus]], will work without electricity. Others, like the electronic calculator, use batteries. Some calculators are simple, and can only [[addition|add]], [[subtraction|subtract]], [[multiplication|multiply]] and [[Division (mathematics)|divide]], and sometimes take [[square roots]]. Scientific calculators can do many other things, such as use [[exponents]] (or powers or indices) and [[trigonometry]] functions. A printing calculator can print its results. == Pocket calculator == [[Image:Casio_calculator_JS-20WK_in_201901_002.jpg|thumb|upright|An electronic pocket calculator with a [[liquid crystal display]].]] A pocket calculator is a small calculator that helps people do [[arithmetic]]. It is so small that it can be put in a [[pocket]]. Its most common use is for [[addition]], [[subtraction]], [[multiplication]], and [[Division (mathematics)|division]]. Many pocket calculators are powered by [[solar cell]]s. They are commonly seen in schools and businesses and can be used quickly and efficiently for simple mathematical problems. Other names are 'miniature calculator' or 'mini calculator'. == Scientific calculator == A scientific calculator can do more things. It can often use [[exponents]] (or powers or indices), [[Pi (mathematical constant)|pi]], [[trigonometry|trigonometric ratios]], and the [[order of operations]]. Scientific calculat