HP 35s

Fractions 5-3
Accuracy Indicators
The accuracy of a displayed fraction is indicated by the  and  annunciators at
the right of the display. The calculator compares the value of the fractional part of
the internal 12–digit number with the value of the displayed fraction:
 If no indicator is lit, the fractional part of the internal 12–digit value exactly
matches the value of the displayed fraction.
 If  is lit, the fractional part of the internal 12–digit value is slightly less than
the displayed fraction — the exact numerator is no more than 0.5 below the
displayed numerator.
 If  is lit, the fractional part of the internal 12–digit value is slightly greater
than the displayed fraction — the exact numerator is no more than 0.5 above
the displayed numerator.
This diagram shows how the displayed fraction relates to nearby values — 
means the exact numerator is "a little above" the displayed numerator, and 
means the exact numerator is "a little below".
Entered Value Internal Value Displayed Fraction
2
3
/
8
2.37500000000  
14
15
/
32
14.4687500000  
54
/
12
4.50000000000  
6
18
/
5
9.60000000000  
34
/
12
2.83333333333   
15
/
8192
0.00183105469   
12345678
12345
/
3
12349793.0000

16
3
/
16384
16.0001831055

0 7/16
6
16
/
0 7/16 0 7/16
(0.40625)
6.5
16
/
7
16
/
7.5
16
/
8
16
/
(0.43750) (0.46875)