Rule
I of IS 2:1960: If
the figure next beyond the last figure/place to be retained is <
5, the figure in the last place retained is left unchanged.
(In all of the examples below, blue
coloured numeral shows “last
place to be retained” & brown
coloured numeral shows "figures
beyond the last place to be retained that have been taken
into consideration for rounding off")
|
|
Value
|
Rounding
off to nearest
|
Rounded
off value |
Explanation
|
|
4.36
|
1
|
4
|
Here
figure in the last place to be retained is 4
(since it is being rounded off to nearest 1). The figure after 4 is 3;
which is less than 5. So figure in the last place retained is left
unchanged i.e. 4 remains as 4 |
| 2.355
|
1
|
2
|
Explanation
same as above (since 3<5,
last place retained remains unchanged at 2) |
| 15.205
|
0.1
|
15.2
|
Explanation
same as above (since 0<5,
last place retained remains unchanged at 2) |
|
Rule
II of IS 2:1960: If
the figure next beyond the last figure/place to be retained is >
5 or is 5 followed by any figures other than 0, the figure in the last
place retained is increased by 1.
|
| Value
|
Rounding
off to nearest
|
Rounded
off value |
Explanation
|
| 9.625
|
1
|
10
|
Here
figure in the last place to be retained is 9 (since it is being rounded
off to nearest 1). The figure after 9
is 6;
which is more than 5. So figure in the last place retained is increased
by 1 i.e. 9 becomes 10 |
| 2.651
|
0.1
|
2.7
|
Here
figure in the last place to be retained is 6
(since it is being rounded off to nearest 0.1). The figure
after 6
is 5 followed
by 1
i.e. 5 followed by non-zero number only; So figure in the
last place retained is increased by 1 i.e. 6 becomes 7
|
| 0.3552
|
0.01
|
0.36
|
Here
figure in the last place to be retained is (since it is being rounded
off to nearest 0.01). The figure after 5
is 5
followed by 2
i.e.
5 followed by non-zero number only; So figure in the last
place retained is increased by 1 i.e. 5 becomes 6 |
| 12.545001
|
0.01
|
12.55
|
Here
figure in the last place to be retained is (since it is being rounded
off to nearest 0.01). The figure after 4
is 5
followed by 0,
0, 1 i.e.
5 followed by at least 1 non-zero number (i.e. all the numbers
following 5 are not zero);. So figure in the last place
retained is increased by 1 i.e. 4 becomes 5 |
Rule III of IS 2:1960:
If
the figure next beyond the last figure/place to be retained
is 5 alone or is 5 followed by zeros only, the figure in the last place
retained is:
(a) increased
by 1 if it is odd
(b) left
unchanged if even; zero is to be regarded
as even number for this purpose.
|
| Value
|
Rounding
off to nearest
|
Rounded
off value |
Explanation
|
| 7.5
|
1
|
8
|
Here
figure in the last place to be retained is (since it is being rounded
off to nearest 1). The figure after 7
is 5 alone;
So figure in the last place retained is increased by 1 (i.e. 7 becomes
8) since 7 is an odd number. |
| 8.5 |
1
|
8
|
Here
figure in the last place to be retained is 8
(since it is being rounded off to nearest 1). The figure after 8
is 5
alone;
So figure in the last place retained is left unchanged (i.e. 8 remains
8) since 8 is an even number. |
| 13.405
|
0.01
|
13.40
|
Here
figure in the last place to be retained is 0
(since it is being rounded off to nearest 0.01). The figure
after 0
is 5
alone;
So figure in the last place retained is left unchanged (i.e. 0 remains
0) since 0 is considered as an even number for this purpose.
|
| 12.545000
|
0.01
|
12.54
|
Here
figure in the last place to be retained is 4
(since it is being rounded off to nearest 0.01). The figure
after 4
is 5
followed
by three zero numbers (i.e. none of the numbers following 5 is
non-zero); So figure in the last place retained is left
unchanged (i.e. 4 remains 4) since 4 is an even number
|
| 12.555000
|
0.01
|
12.56
|
Here
figure in the last place to be retained is 5
(since it is being rounded off to nearest 0.01). The figure
after 5
is 5
followed
by three zero numbers (i.e. none of the numbers following 5 is
non-zero); So figure in the last place retained is
increased by 1 (i.e. 5 remains 6) since 5 is an odd number
|
