1. CS 105
Spreadsheet Computations
What is a cell? What is a range?
What is a formula?
What is a circular reference?
What’s the difference between copying text
and copying a formula?
CS 105 Spring 2011
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2. Manipulating Data
• A calculator can store two numbers and do
simple manipulations
current
M
memory clear
memory recall
memory set
memory plus
Mem clear
Set M to zero
M=0
Mem recall
Set current to M
current = M
Mem set
Set M to current
M = current
Mem plus
Set M to M + current M = M + current
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3. Manipulating Spreadsheet Data
• A workbook contains worksheets(spreadsheets).
A spreadsheet stores data organized in cells,
and can do complex data manipulation.
Name box
active cell
formula bar
fill handle
The cell location is referred to as its cell reference.
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4. Cell Ranges
An adjacent range is a rectangular block of cells and can
be as small as a single cell.
G2 : G8
Single
Column
Range
column letters
A1
Single cell
A3 : E3
Single Row Range
B6:E13
Read as
“B6 to
E13”
Row numbers
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5. Cell contents can be either
Data or Formulas
• Data can be either Numeric or Strings:
– numbers (e.g. 25.32, -56, $78, 1.02E-3, 5%, 1/1/2011)
– strings (e.g., Total, Angelina Jolie, 1-217-244-0000)
• Formulas always begin with an equals = and can contain
operators, data, cell references, ranges and functions,
e.g.
= 1+ A1
• Cells also have formatting attributes
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6. Numbers as strings
• Some “numbers” are
entered as text
(strings):
– zip codes
– phone numbers
– social security
numbers
– Such numbers do not
get involved in
computation.
By default Excel left-justifies strings and right-justifies numbers.
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7. Date Entries
• Dates are a special kind of number – Try
01/01/1900
• Two-digit year values 00 through 29 are
interpreted as the years 2000 through 2029
• Year values 30 through 99 are interpreted
as the years 1930 through 1999.
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10. Operators in Formulas
• Arithmetic operations (in order of precedence)
– parentheses
( )
– negation (as in -1)
– exponentiation
^
– multiplication, division
*
/
– addition, subtraction
+
-
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11. Hierarchy of Arithmetic Operations in
Excel
– Scan the formula from left to right
– Evaluate what is in parentheses first
– Operations of highest priority are done first
– Evaluate from left to right operations of equal priority.
= B1 + B2 * C3
= -C1 ^ A1
= (B3-A1)*A1^2/B2
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12. Functions in Formulas
• =TODAY()
• =MONTH( March 7, 2006)
• =MONTH(A1)
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13. Bad Formulas!!! Circular References
• When a formula references itself
(either directly or indirectly) there is
a Circular Reference
• When this happens, Excel warns you
several times!!
• BAD:
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14. Copying formulas
• Example: In a Sudoku board, every row must sum to 45
– more conditions, but we’ll stick to this for now
• Copy formula to the remaining rows (formula changes)
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15. When you cut and paste a
cell that is referenced in a formula,
then again the formula changes
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16. Copying/Pasting Formulas
Relative Cell Reference
• A cell reference that adjusts automatically
when it is copied.
• By default, formulas that you enter use
relative cell references.
• For example:
B to D = moved 2 Columns
2 to 5 = moved 3 Rows
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17. Mixed Cell References
• A cell reference that refers to an exact
location on the worksheet and does not
adjust when copied.
• Cell reference is preceded by a dollar sign.
• For example:
=($B$5 + $C7) * D$9
Absolutely column b
and absolutely row 5
Absolutely
column c
CS 105 Spring 2011
Absolutely
row 9
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19. To Summarize:
• What is a cell? What is a range?
• What is a formula?
• What is a circular reference?
• What’s the difference between copying text
and copying a formula?
CS 105 Spring 2011
# 19
