Lecture 5 Spreadsheets and Presentations

©1999 Addison Wesley Longman6.2 The Spreadsheet The spreadsheet is a matrix that consists of: –Worksheet (a spreadsheet document) –Columns (alphabetical horizontal divisions) –Rows (numbered vertical divisions)

©1999 Addison Wesley Longman6.3 The Spreadsheet –Cells (the intersection of a row and column) –Addresses (column letter and row number, e.g., C12)

©1999 Addison Wesley Longman6.4 The Worksheet The worksheet is a grid formed by columns and rows and can contain: –Values (or numbers such as 4, -76, $120.00). –Labels (words that explain what the numbers mean such as Food). ExpensesAmount Rent Food Utilities Total $400 $250 $120 $760 AB

©1999 Addison Wesley Longman6.5 Entering Text

©1999 Addison Wesley Longman6.6 Entering Numbers

©1999 Addison Wesley Longman6.7 The Worksheet –Formulas (a step-by-step procedure for calculating a number, e.g. =Sum(B2:B4).

©1999 Addison Wesley Longman6.8 Specifying a range of cells

©1999 Addison Wesley Longman6.9 Cell Types Numerical Values (simply a number) –displayed right justified within the cell by default –may contain math operations eg. =6-3+7 is displayed as 10 Numeric Formula: –formulae may refer to values in other cells –for example, B6 is =B3+B2 or +B3+B2 –values in B2 and B3 are added, result being displayed in B6

©1999 Addison Wesley Longman6.10 Cell Types (cont.) Text (or Labels): –anything else, though usually a heading –treated as a sequence of individual characters –to enter numbers as text, enter one of the quotes as first character. –for example, '1234 entered as one two three four Blank –mathematical value of zero.

©1999 Addison Wesley Longman6.11 Some common functions =SUM(range) = sum of all cells within the range =AVERAGE(range) = average of non-blank cells within range =MIN(range) = Returns minimum value in range =MAX(range) =TODAY() = just date =NOW() = date and time =IF(condition, true, false)

©1999 Addison Wesley Longman6.12 Spreadsheet Features Automatic replication of values, labels, and formulas (relative versus absolute references) Automatic recalculation

©1999 Addison Wesley Longman6.13 Relative References Deafult type Copy command automatically adjusts cell references in formula as it copies. Relative references are adjusted –column references as copies across –row references as copies up/down.

©1999 Addison Wesley Longman6.14 Absolute References Absolute references are not changed –needed when the value is taken from one cell –e.g. interest rate Add $ sign to make absolute reference –$H$4 always refer to fixed location –H$4 keeps row reference fixed on copying –$H4 keeps column reference fixed when copying

©1999 Addison Wesley Longman6.15 Spreadsheet Features Linking (reflect changes in related worksheets). Database capabilities.

©1999 Addison Wesley Longman6.16 Spreadsheet Features Predefined functions (e.g., SUM, AVG, SQRT). Macros (custom design your own feature) Templates (ready- to-use worksheets).

©1999 Addison Wesley Longman6.17 “What If?” Questions Spreadsheets allow you to change numbers and instantly see the effects of those changes. –“What if I enter this value?” Equation solvers –Some spreadsheets generate data needed to fit a given equation and target value.

©1999 Addison Wesley Longman6.18 “What If?” Questions Validators - the equivalent of spelling and grammar checkers for spreadsheets.

©1999 Addison Wesley Longman6.19 Spreadsheet Graphics: From Digits to Drawings Charts allow you to turn numbers into visual data: –Pie charts (show relative proportions to the whole) –Line charts (show trends or relationships over time)

©1999 Addison Wesley Longman6.20 Spreadsheet Graphics: From Digits to Drawings –Bar charts (use if data falls into a few categories) –Scatter charts (use to discover, rather than to display, a relationship between two variables)