## Basic Calculations/Order of Operations

Binary operations (add, subtract, multiply, divide) are entered in the calculator, as you would write them on paper. For example, to compute 34 + 7, in the entry line type

Unary operations (operations that require only one input) also are entered, as you would write them. To find the square root of 25, in the entry line type

The negative sign must not be confused with the subtraction sign. When subtracting two numbers use the black Ð key (located above the + key); when negating a number, use the grey key (located to the left of the ENTER key).

The order of binary arithmetic operations is programmed into the calculator just as in algebra. Operations enclosed within parentheses are always done first. Since parentheses have the highest priority, use parentheses whenever in doubt. After parentheses, arithmetic operations are done from left to right in the following order:

exponentiations are done first,
multiplications and divisions are done second,
additions and subtractions are done third.

For example, the expression, 1 + 2 x 3 is calculated as 1 + (2 x 3) = 7.

Further note that, in general, for a given function f, f (a + b) f (a) + f (b). In particular,