1 7 significant figers

Assalam o Alaikum to every one I hope so that you and your family with the bless of ALLAH ALMIGHTY will be safe and sound in this COVID situation. Purpose of this video is to learn at home #to stay at Home. In this video i'll talk about basic #Significant figures this video lesson also contain method of #rounding off digits. All topic contains Definitions, examples, formulas and units. you can also questions about any question related to topic in comment section or contact me at my email #bilalhassancht@gmail.com or inbox me at #bilalhassancht@gmail.com/facebook.com
for previse lesson length measurement instruments
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#1.7 SIGNIFICANT FIGURES
All the accurately known digits and the first doubtful digit in an expression are called significant figures. E.g 190
It reflects the precision of a measured value of a physical quantity.
For example, a student measures the length of a book as 18 cm using a measuring tape. The numbers of significant figures in his/her measured value are two. The left digit 1 is the accurately known digit. While the digit 8 is the doubtful digit for which the student may not be sure.
Another student measures the same book using a ruler and claims its length to be 18.4 cm. In this case all the three figures are significant. The two left digits 1 and 8 are
accurately known digits. Next digit 4 is the doubtful digit for which the student may not be sure.
The significant figures are all the digits that are known accurately and the one estimated digit. More significant figure means greater precision.
The following rules are helpful in identifying significant figure:
(i) Non-zero digits are always significant.
e.g 1,2,3,4,5,6,7,8,9

“Zero” may or may not be significant

When “Zero” is significant.

(ii) Zeros between two significant figures are also significant.
101, 10003, 23402
(iii) Final or ending zeros on the right in decimal fraction are significant.
123.00 , 102.0

When “Zero” is not significant.

(iv) Zeros written on the left side of the decimal point for the purpose of spacing the decimal point are not significant.
0000234 , 0.00123

#Rounding the Numbers

(i) significant digits in the figure. lf the last digit is less than 5 then it is simply dropped. This decreases the number of significant digits in the figure.
For example, 1.943 is rounded to 1.94 (3 significant figure)
(ii) If the last digit is greater than 5, then the digit on its left is increased by one. This also decreases the number of significant digits in the figure.
For example, 1.47 is rounded to two significant digits 1.5
(iii) If the last digit is 5, then it is rounded to get nearest even number or odd number.
For example, 1.35 is rounded to 1.4
and 1.65 is also rounded to 1.6

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