Order of operations
The calculator follows the usual order of operations, in ten levels. Brackets come first. Then functions that open a bracket, such as sine and log. Then what is written after a value: squares, powers, roots, factorial and per cent. Then fractions, then the negative sign, then estimated values in statistics, then multiplication where the times sign is left out. Then permutations and combinations, then multiplication and division, and last, addition and subtraction. When two operations have the same priority, the calculator works from left to right.