# Physics Lesson 1.3.4 - Why are significant figures so important in measurements?

Welcome to our Physics lesson on Why are significant figures so important in measurements?, this is the fourth lesson of our suite of physics lessons covering the topic of Significant Figures and their Importance, you can find links to the other lessons within this tutorial and access additional physics learning resources below this lesson.

## Why are significant figures so important in measurements?

From what we said above, it is clear that 5.700 kg is not the same thing as 5.7 kg. The first number has 4 significant figures. It is measured more accurately than the second one. Indeed, the second value can be a number ranging from 5.650 kg to 5.749 kg. All these numbers when rounded to 1 decimal place give 5.7 kg. This is not the case of the first number. It cannot be neither 5.699 nor 5.701 but exactly 5.700 kg. Its accuracy is 1g while the accuracy of 5.7 kg is 0.1 kg (or 100 g). Although in mathematics these two numbers are equal, in physics they are different because they are obtained by using apparatuses with different degree of accuracy.

## More Significant Figures and their Importance Lessons and Learning Resources

Units and Measurements Learning Material
Tutorial IDPhysics Tutorial TitleTutorialVideo
Tutorial
Revision
Notes
Revision
Questions
1.3Significant Figures and their Importance
Lesson IDPhysics Lesson TitleLessonVideo
Lesson
1.3.1What are significant figures?
1.3.2How to find the number of significant figures in a given numerical value?
1.3.3How to round up a number to the required number of significant figures?
1.3.4Why are significant figures so important in measurements?

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