Display Numbers to a Specified Precision
You can use the sigform() and decform() functions to display numeric values to a specified number of significant digits or decimal places.
 sigform()
 Displays a value rounded to the specified number of significant digits. If needed, "e" notation is used.
 decform()
 Displays a value rounded to the specified number of decimal places.
Note: If your answer key uses
$SIGFIGS
or $DECFIGS
to
require a specified precision, the answer key will be displayed to the correct
precision automatically without using the sigform() or
decform() functions. Example Question Using sigform()
The following table summarizes an actual question.
QID 
1940827 

Name 

Mode 
Numerical 
Question 
<eqn> # Pick two different significant figures for the measurements ($m_sigfigs,$v_sigfigs) = pick(2,2..5); # Randomize measurements & round to the specified significant figures $mass = sigform(randnum(300000,1200000,1)/100000,$m_sigfigs); $volume = sigform(randnum(106000,110000,1)/100000,$v_sigfigs); # Calculate answer key and determine correct significant figures $density = $mass/$volume; $d_sigfigs = min($m_sigfigs,$v_sigfigs); '' </eqn> In the lab, you measure the displacement of a metal sphere as <eqn $volume> liters.<BR/> You also determine its mass to be <eqn $mass> kg.<BR/> Calculate its density. <_> kg/l 
Answer 
<EQN $SIGFIGS=$d_sigfigs; $density> 
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Example Question Using decform()
The following table summarizes an actual question.
QID 
1944303 

Name 

Mode 
Numerical 
Question 
<eqn> # Pick the number of decimal places for the problem ($decimals) = pick(1,2..4); # Randomize addends $a = decform(randnum(100000,999999,1)/10000,$decimals); $b = decform(randnum(100000,999999,1)/10000,$decimals); '' </eqn> <watex>\begin{array}{r} $a \\ + $b \\ \cline{00} <_> \end{array}</watex> 
Answer 
<EQN $SIMPLIFIED=1; decform($a + $b, $decimals)> {tab} 0 
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Tip: For known constants, you can enclose the value in single quotes to
store both the value and the precision with which you specified it. For example,
$e = '2.718';
assigns a value to $e with four significant
digits.