Algorithmic Problems - University of Tennessee at Martin

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.
Open Word and type the following:
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
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 /
• 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
Result of step 1, in Word
Open Excel and Copy Paragraph into
Cell A2
Create variable names
• Insert a new column B
• Type variable names (useful to create range
Purchase year
Life in years
Life in hours
(leave 2nd use of Purchase year blank)
Purchase year hours
Second year
Second year hours
Step 2: Express numeric variables as
numbers and text.
• For calculations, replace any text variables with
• 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
Result of step 2:
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
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
– Can’t have salvage in excess of cost
– (view example sheet)
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
– 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
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)
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”
– 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.
Step 6:
• Copy into test pool as a question!
• Hit Calculate Now on formula bar and enter
that result as a question, too!
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!)
MC Questions
• See 2nd 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!

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