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161- What are formulas?
A formula is an equation that performs operations on
worksheet data. You can use an Excel 2007 formula to perform
mathematical operations, such as addition and multiplication, or they can
compare worksheet values, join text, averaging a student’s test results, etc.
A
basic formula format will start with an equals sign (=) followed by one or more
operands, separated by one or more operators. Operands can be values,
text, cell references, ranges, defined names, or function names. Operators are symbols used to represent the various arithmetic and comparison operations
you can perform on the operands
In Microsoft Excel 2007, operators are executed in this
order:
To
enter a formula:
1)
Place
the cursor in the cell where the formula will appear, i.e.E5.
2)
Enter
an = sign. All Excel formulas start with the ‘equal’ sign.
3)
Enter
the expression that will produce the result you want. This can consist of
operands, values, variables, and symbols which represent mathematical
procedures such as + or – to add and subtract, e.g. A5+C5.
4)
When
the formula is complete, press Enter. The result of the formula will be
calculated and displayed in the cell E5.
5)
You
can see the formula in the Formula bar at the top of the screen by
placing the cell pointer on the cell E5.
If there is an error in a formula, an error message is displayed which will
begin with a # sign.
162- Order of operations
Overview of formulas:
Formulas are equations that perform calculations on
values in your worksheet. A formula starts with an equal sign (=). For example,
the following formula multiplies 2 by 3 and then adds 5 to the result.
=5+2*3
A formula can also contain any or all of the
following: functions, references, operators, and constants.
Parts of a formula:
A constant is a value that is not calculated. For
example, the date 10/9/2008, the number 210, and the text "Quarterly
Earnings" are all constants. An expression, or a value resulting from an
expression, is not a constant. If you use constant values in the formula
instead of references to the cells (for example, =30+70+110), the result
changes only if you modify the formula yourself.
Using calculation operators in formulas:
Operators specify the type of calculation that you
want to perform on the elements of a formula. There is a default order in which
calculations occur, but you can change this order by using parentheses.
Types of operators:
There are four different types of calculation
operators: arithmetic, comparison, text concatenation, and reference.
Arithmetic operators:
To perform basic mathematical operations such as
addition, subtraction, or multiplication; combine numbers; and produce numeric
results, use the following arithmetic operators.
Comparison operators:
You can compare two values with the following
operators. When two values are compared by using these operations
The result is a logical value either TRUE or FALSE.
Text concatenation operator:
Use the ampersand (&) to join, or concatenate, one
or more text strings to produce a single piece of text.
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