Basic Calculations/Order of Operations


Basic calculations are done from the MAT screen. Press MENU 1 to access the RUN-MAT screen. Binary operations (add, subtract, multiply, divide) are entered in the calculator as you would write them on paper. For example, to compute 34 + 7, type

3 4 + 7 EXE

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

SHIFT 2 5 ) EXE

The negative sign must not be confused with the subtraction sign. When subtracting two numbers use the - key (located above the EXE key); when negating a number, use the ( - ) key (located left of the EXE 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,

(a + b)2 a 2 + b 2
(a + b)n a n + b n for n 1
ea+b ¹ ea + eb
ln(a + b) ¹ ln(a) + ln(b)
sin(a + b) ¹ sin(a) + sin(b)