# Using Spreadsheet Text Functions and Data Validation to Create Algorithmic Questions Mary Geddie & Richard Griffin University of Tennessee Martin.

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Using Spreadsheet Text Functions and Data Validation to Create Algorithmic Questions Mary Geddie & Richard Griffin University of Tennessee Martin

Open Word and type the following: A company purchased equipment for \$325,000 on January 2, 2010. The company expects the equipment to last for ten years or 80,000 hours of operation, with an estimated salvage value of \$10,000. During 2010, the equipment was in operation for 7,000 hours. In 2011 the equipment was in operation for 8,800 hours. 2

Open Word and type the following: Requirements Compute the depreciation expense relating to the equipment for 2010 and 2011 using the following depreciation methods: a. Straight-line b. Double-declining-balance c. Units-of-production 3

Step 1: separate text from variables Begin with a Word paragraph. With the paragraph highlighted, set a Right tab at 6 inches (Home / Paragraph dialog box / Indents and Spacing tab / Tabs). Read through problem, identifying each variable that may be changed in alternate versions. Immediately after each variable, hit the Enter key. Insert a Tab immediately before each variable. Keep any spaces with the text so that the variable is stripped. Any characters that Excel recognizes as number formatting, such as \$’s or commas, are kept with the variable 4

Result of step 1, in Word 5

Open Excel and Copy Paragraph into Cell A2 6

Create variable names Insert a new column B Type variable names (useful to create range names) Cost Purchase year Life in years Life in hours Salvage (leave 2 nd use of Purchase year blank) Purchase year hours Second year Second year hours 7

Step 2: Express numeric variables as numbers and text. For calculations, replace any text variables with numbers. Grammarians will want the final result to follow the rule that numbers <= 10 are spelled out (first, five, etc.) Use column D for the text version of values Nested IF statement with a blank as the final “False” =IF(B4=10,"ten",IF(B4=9,"nine",IF(B4=8,"eight",IF(B4=7," seven",IF(B4=6,"six",IF(B4=5,"five",IF(B4=4,"four",IF(B4= 3,"three",IF(B4=2,"two",""))))))))) 8

Result of step 2: 9

Step 3: Add range names Highlight Variables in Column C. (only highlight the first instance) Formulas/ Create from Selection (in the Defined Names group) / Left Column 10

Step 4: express relations between variables as calculations or data validation limitations. Replace all the years in column C (except Purchase year in cell C3) with formulas Create data validation rules to maintain the internal consistency of the problem – Can’t have more than 365 x 24 hrs of operation in any year – Can’t have salvage in excess of cost – (view example sheet) 11

Step 4 I use cell color to distinguish cells – require data entry cell uses style “Note” – Formula result cell style “Bad” – All cells except data entry cells s/b locked (after completion of spreadsheet) I only used data validation per se for data entry cells – Try entering a 1-year life in cell C4 Min / Max columns provide for internal consistency for formula cells. – Additional data in rows 20 & 21 helps determine min/max values -- another way to change the problem 12

Step 4 I used Rand and RandBetween functions in the formula cells – Which you might not want to do! Set spreadsheet to limit recalculation if using – Formulas / Calculation options Analysis of formula for Life_in_Hours: RandBetween(min,max) Round(result of RandBetween) Min(Rounded result, max value) 13

Step 5: Concatenate the text strings I use Concatenate function as shown in A28 of example spreadsheet (some people use & ) Cells in columns C and D are not text strings, and must be converted to text using the TEXT function when they appear in the list of cells Syntax is =TEXT(value,format_text). – format_text argument must be enclosed in quotation marks. – Column D variables are converted to text strings with “aaaa” formatting, – Column C are all dollar values and use “\$0,000” formatting. – Excel Help can help! To proof-read the CONCATENATE formula, notice that the variables from Column A begin with A2 and are listed in order by row, interspersed with either the cell from column C or the cell from column D for that row, but never both column C and D from the same row. 14

Step 6: Copy into test pool as a question! Hit Calculate Now on formula bar and enter that result as a question, too! 15

Step 7: Solutions Use the Range Names in your formulas – Easy and fun! – Type = and start typing the word, then select the Range Name from the popup menu – Type: =(Cost-Salvage)/Life_in_years – Range Name advantage is automatic absolute referencing (great for MC version!) 16

MC Questions See 2 nd tab “multiple choice” First part of question stem is in cell A1 – Tied to previous spreadsheet Requirement statement is with MC answers – Also tied to previous spreadsheet Example: A3 uses Purchase_year variable Column E documents why the MC answers are good distractors, and are for the question writers, not for students! 17

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