LA283   Section 2
				Lotus 1-2-3 for Windows Version 5.0
				   Hendrickson-Smith: Lecture 2 
					April 18, 1996

				
				    Working with Numbers

Cell References; The Order of Precedence;  Functions and Formulas; Automatic Recalculation


1. Cell References (Addressing): When using formulas and functions, cells are referenced 
   by the intersection of their column letter and row number. There are three types 
   of addressing used to reference cells: absolute, relative, and mixed.
	A. Absolute reference: an absolute address always refers to the same
           cell regardless of where the formula is moved; written as $B$1.
	B. Relative reference: a relative address refers to a cell based on its
           location relative to a formula; written as +B1. The reference changes if 
           the formula is moved.
	C. Mixed reference: a mixed address is  a reference to a cell in which parts 
           of the address are absolute and parts are relative; written as $C4. 
           For example, if you copy the reference $C4, the column letter 
           stays the same while the row number changes.

2. The Order of Precedence (Operation): the order in which arithmetic operators are evaluated.
		^		exponentiation	
		* and /		multiplication and division
		+ and -		addition and subtraction

	If two operators have equal precedence, 1-2-3 evaluates them in order from 
	left to right. Parentheses can be used to alter the order of precedence. 
	1-2-3 evaluates the portion of a formula enclosed by parenthesis before it 
	evaluates the remainder of the formula.

	Example:

	3*2+4/8-3	(3*2)+4/(8-3)		3*(2+4)/8-3		(3*2+4)/(8-3)
	6+.5-3		6+4/5			3*6/8-3			(6+4)/5
	6.5-3		6+.8			18/8-3			10/5
	3.5		6.8			2.25-3			2
						.75

3. 1-2-3 Formula: an equation that calculates a new value using existing values in cells
   within the worksheet. Using formulas allows for automatic recalculation whenever the
   original data change(s). The following arithmetic operators are valid in a formula.

		+ addition		*	 multiplication
		 - subtraction	
		/  division		^  	exponentiation

	Formulas are preceded with a + or -  sign or with one of the special characters
	listed on page L68 of the "Shelly Cashman" module.

	Examples:
		+C5 - (C10/C20)
		+C5*.2
		+D10^

4. 1-2-3 Functions
		A. @function--> set of predefined instructions (algorithim) which perform
                                common operations
			****always preceded by the @symbol******
			examples: @sum	@max   @avg  @median

		--> click the function selector on the Edit Line to get a menu of
                    categories and categories within functions	

		B. Formulas and functions are usually used to calculate a range of cells
			****range--> a rectangular group of cells in a worksheet****
			A1..C10

5.  Copying formulas and functions: it is often useful to copy a function or formula 
    to another cell or cells.
		*****Copy the function @sum(A4..A10) in A12 to B12 C12 and D12 ****
		The range in the function will change based on its RELATIVE position

		--select A12
		--click and drag through D12 (the mouse pointer changes to an 
		  arrow pointing to a picture of a cell)
		--the mode changes from Ready to Point
		--click with the right mouse button
		--click on copy right

6. Automatic Recalculation: when a value in a file changes, 1-2-3 recalculates all other 
   cells dependent on the changed value. The default mode is Automatic, although it can 
   be turned off (changed to Manual). For very large spreadsheets, Automatic
   recalculation may be very slow (dependent in part on your hardware and configuration).

	A. Turning Automatic Recalculation off
		Click Tools--> User Setup 
		Click the Recalculation Button
		Click Manual
		Note: when Manual is chosen, the mode indicator displays calc when a cell
		      has been changed.
		To recalculate when manual is chosen, type F9.