# data[].attributes.body
When two or more numbers are added and subtracted the final result should be reported to the same number of decimal places as that of the original number with minimum number of decimal places
Ex: A =  22.678  B =  234.5
A +B  = 22.678  + 234.5 =
= 257.178
= 257.2
Ex :   A =  345.7865    B =  100.57
A - B =  345.7865 - 100.57
=  245.2165
= 245.22

# data[].attributes.body
When two or more numbers are multiplied and divided ,the final result should be reported to the same number of significant figures as that of the original number with minimum number of significant figures
Ex:  A = 23.456    B = 1.78
A.B = 23.456 * 1.78
= 41.75168
= 41.8
Ex:   Mass = 5.74g  Volume = 1.2cm cube
Density = Mass/Volume
= 5.74/1.2
= 4.783
= 4.8g/cmcube

# data[].attributes.headline
 Rule 1: How to calculate percentage error in arithmetic operations

# data[].attributes.subject
 Rule 1: How to calculate percentage error in arithmetic operations

# data[].attributes.body
To calculate the  percentage error in uncertainty  of Area when a rectangular sheet of length l and breadth b is given
l = 16.2 +- 0.1cm
% error in l = Delta l/l * 100
= 0.1/16.2 * 100
= 0.6%
% error in l = 16.2 +- 0.6%
b = 10.1 +- 0.01cm
% error in b = Delta b/b * 100
= 0.01/10.1 * 100
= 0.1%
% error in b = 10.1 +- 0.1%
Combining the % error in length and breadth we calculate the % error in area A as A = l * b
= (l +- Delta l)(b +- delta
b)
=(16.2 * 10.1) +- (delta l/l + delta
b/b)
= 163.62 +- 1
=  164 +-  1cm square

# data[].attributes.body
If a set of experimental data is specified to n significant figures, a result obtained by combining the data will also be valid to n significant figures
Ex: l = 1.02   b  = 1.02
A = l * b
= 1.02 * 1.02
= 1.0404
= 1.04msquare

* Sometimes in subtraction and addition of quantities the law applies and it reduces so it is not possible to get the same number of significant digits in the answer
Ex:   m1 = 12.9g   m2 = 7.06g
Delta m = (m1 - m2)
= 12.90 - 7.06
= 5.84
= 5.8g

# data[].attributes.body
The relative error of a value of a number specified to n significant figures depends not only on n but also on the number itself
Ex;  m1 = 1.02  +-  0.01
Relative error = +- deltam/m *
100
=+- 0.01/1.02 * 100
= +- 1%

Ex: m2 = 9.89g +- 0.01g
Relative error  = +-deltam2/m2
* 100
= 0.01/9.89 * 100
= +- 0.1%

* In a multistep computation ,the intermediate step can have an increase of one significant figure
Ex:  N = 9.58
R = 1/9.58 = 0.1044
N' = 1/0.1044 = 9.58

# data[].attributes.headline
1. All zeroes to the right of a non-zero digit but to the left of an understood decimal point are significant.

# data[].attributes.subject
1. All zeroes to the right of a non-zero digit but to the left of an understood decimal point are significant.

# data[].attributes.body
Ex : 6487000.
The above number has 7 significant figures

2. When a number greater than or equal to one then all zeroes on the right as well as to the left of decimal will be significant figures.
Ex: 2.020200 - 7
10.0200 -  6

# data[].attributes.body
1. 21.34 = 21.3
2. 45.56 = 45.6
3 . 82.5 = 82.0
3. 67.45 = 67.4
4 71.75 = 71.8
5. 8284000 = 8280000
6. 248337 = 248000