
Overview 
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There are literally
hundreds of calculators on this site, and several tools have
been provided to assist with their navigation and usage.
Each calculator page is divided into three
sections, "Formula", "Units" and "Calculator"
as described below. Where a calculation requires multiple
formulae to be combined, click on the "open another"
link at the bottom of the "Overview" section to
open another copy of the same calculator in a new Browser
window, and any common values can be copied from the result
of one page, and pasted into the variable entry box of another
page using either the operating system Clipboard.(In MS Windows
use the "Ctrl +C" keyboard shortcut to copy, and
the "Ctrl + V" keyboard shortcut to paste.)
There will be times where the required information
will require a combination of more than one calculation /
data page, and the "Cookie Clipboard" allows for
the storage of up to 10 values. This functionality requires
that your Browser has "Cookies" enabled. Another
benefit of this clipboard is that the values are saved locally,
so that they will be available when you return to this site.
Note! All of the calculator
pages within this site are written in Javascript, and require
that this functionality is enabled in your Browser.
Note! Calculator
Under Construction. (Updating text to explain additional
functions)

Data
Entry Controls 
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The table below lists
the types of control used to accept user input with a brief
explanation of their usage.
Note! Some controls are marked
as "Read Only", and will not accept input. These
controls are displayed differently. Even if a control is
"Read Only", its contents can still be copied to
the "Cookie Clipboard", or the "MS Windows
Clipboard".

Cookie
Clipboard 
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In order to exchange values between
pages, the "Calculator", "Unit Conversion",
and some "Tables" have links to a "Cookie
Clipboard" which stores up to 10 values. These values
use the "cookies" function of your Browser, and
they are stored even between sessions (for up to one year).
As a new value is added, all other values will be moved down
one place with the last value being deleted. so that data
can easily be exchanged between the controls on their pages
without the need for retyping. This Clipboard also stores
the last ten values so that they will be available when you
return to the G.I.F.T. web site.
It uses cookies, which are small text files stored on your
computer, therefore if you have cookies disabled on your
Browser, the Cookie Clipboard will not function.
Displays the "Cookie
Clipboard" in a new window. Note!
If it is already open, the contents will be refreshed. 
Copies the value in the adjacent control to the
"Cookie Clipboard". 
Pastes the last entry from the Cookie Clipboard
into the adjacent control. 
See Also:
Cookie
Clipboard Overview (In depth explanations)

Colour
Coding 
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To assist readability,
the individual components of the formula are colour coded.
This helps to distinguish between characters that could be
misinterpreted such as l (lower case "L"), 1 (numeral
one), and / (forward slash). eg l = 1
/ 100.
All formulae and variables use the font "Times New Roman"
which has "ornaments" at the end of each line of
the character which makes it easier to distinguish
between characters.
Variable names are in blue italic, eg A,
a, l
Numeric values are in red, eg 23,
100,
1
Operators are in green, eg +,
, /

Accuracy 
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Because the calculators
use Javascript which is handled by the Browser, the accuracy
is dependant on how it is implemented within the Browser.
When using variables with large differences in magnitude
between them (eg a
= 1 000 000 000, b = 0.000
000 001, c = a/ b,
the result will be less accurate as the magnitude between
them increases.
None of the calculators round down values (unless explicitly
noted).

Formula 
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Some of the expressions
may contain additional "seemingly unnecessary"
brackets, however they are there to improve their readability,
or to isolate related components. View the page on Numeric
Order of Operation for information on reducing formula
for entry in a hand held calculators.
Formula sections contains the formula used
to calculate the unknown variable(s), and are in one of two
formats, "Simple" and "Compound".
Simple Formula:
Where there are only three variables the formula
will be presented as a simple list with the required
variable on the left of the equals sign, and
the formula to calculate that variable on the
right of the equals sign.

a
= b
* c
b =
a /
c
c =
a /
b

Compound Formula:
Some calculations have multiple variables
which are related to the same value. eg radius
= diameter / 2. Where this is the case the variables
are arranged in a table, with the formula for
the required value (left column) listed under
the cell containing the known values.
These calculators have a table of
examples: AC Ohms Law Calculator, Trigonometric
Formula Calculator.



Units 
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The combo box at the left of the calculator
allow the variable measurement to be entered
(and converted to) different units. variables
in the formula can be
The measurement units listed in the combo
box are in order of their magnitude from smallest
(top of list) to largest (bottom of list). eg
millimetre appears above metre, which appears
above kilometres.
Where a measurement unit has a defined symbol
it will be enclosed in brackets immediately after
the unit name. Some units have additional text
to differentiate it from similar units, which
is enclosed in square brackets. eg "pint
(pt) [UK]", "pint (pt) [US]".
The units displayed in the combo boxes are
limited to commonly used imperial and metric
units. If additional conversions are required,
the value can be copied to the "Cookie Clipboard"
and pasted into the appropriate converter.

a
= a
b = b
c = c


Calculator 
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Where all variables are required
to solve the formula, (except the unknown) they
have the "Calculate" buttons beside
the variable entry controls. Once these variables
have been entered, press the "Calculate"
button immediately to the right of the variable
required.
The buttons will display the prefix "Calc
by" when the other unknown values are to
be calculated from a given value, and "Solve
by" when the other values will be used to
calculate the value.




Metabolic
Rates 
Notes 
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