Swati Talwar


Significant Figures Study Guide

This study guide on significant figures teaches one how to use significant figures in a measurement. Refer to this guide to know more.


The precision of any number can be communicated by significant figures. Significant figures use different numbers of digits to express the level of precision of a measurement. Use this significant figures crash course to help you learn more about how they work!


A significant figure is the number of digits in the obtained value after rounding off the decimal values. They are often referred to as a quick measurement that contributes to the accuracy level of the value. Zero is said to be an insignificant figure; significant values begin with the first non-zero digit of a number. The number of significant figures obtained after rounding up is called the precision of the number.

significant-digits Source


The conversion of significant figures is easy with the use of a calculator. To do it manually, there are a few simple rules to follow.

  • All non-zero digits are significant figures. The number 22.45 has four significant figures because all of its digits are non-zero.
  • Zeros found between non-zero digits are significant figures. The number 2003 has 4 significant figures because the zeros are between the non-zero digits 2 and 3.
  • Leading zeros are not significant figures. The number 0.14 has 2 significant figures, as does 0.014, 0.0014, and so on.
  • Trailing zeros are significant figures, but only to the right of the decimal point. There are 4 significant figures in 4.000.
  • Trailing zeros in a whole number are significant only if followed by a decimal point. The number 6000 only has one significant figure, but 6000. has 4.
  • For a number in scientific notation N x 10x, only the digits comprising N are significant. 3.45 x 102 and 3.45 x 103 both have 3 significant figures.


  • The significant figures refer to the part, which includes the single-digit numbers from 0 to 9 as the coefficient in expression.
  • Significant figures follow a certain set of rules and accurately work on them.
  • In precision, when the measurement level gets repeated, it gives out the identical result, and the individual measured results agree with each other.


1. What are the 5 Rules of significant figures?

Five rules are:

  • All non-zero digits are significant.
  • Between two non-zero digits, if any zero is placed, it is significant.
  • Leading zeros are insignificant.
  • Trailing zeros without any decimal is insignificant.
  • Any number with scientific notation is said to be significant.

2. How do you do significant figures easily?

Significant figures are non-zero digits, which do not count any leading or trailing zeros. To easily do the crash course sig figs, maintain the identical significant figures while going through the decimal and scientific notations. Other ways to do them are by following pacific and Atlantic rules.

3. What are the rules for counting significant figures?

  • If the next digit to the number is more than or equal to five, then the number is rounded up, while if it is less than five, the number is rounded down.
  • In multiplication and division, maintain the same significant figures.
  • In addition or subtraction, maintain the same number of decimal places.

4. How do you teach significant figures?

Significant figures used in unit conversion Chemistry help one teach and understand them. If you want to round up the 489 to the one significant figure, you can easily obtain 500 as the significant value. For example, is 0.00034 a significant figure? We can say that the zeros to the left side are always considered an insignificant value, and thus only 34 is the significant figure in this value.

Rules-of-significant-figures Source

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  2. Significant Digits Definition: https://www.mathsisfun.com/definitions/significant-digits.html. Accessed 28 Feb 2022.
  3. Significant Figures: https://www.cuemath.com/numbers/significant-figures/. Accessed 28 Feb 2022.
  4. Significant Figures: https://courses.lumenlearning.com/introchem/chapter/significant-figures/. Accessed 28 Feb 2022.
  5. Significant Figures: https://byjus.com/maths/significant-figures/.Accessed 28 Feb 2022.