### Course Content

- Do your assignments.
- Review the above video and then complete the following exercise .
- Or for the FREE subscription complete the following worksheets .

## Objective:

The purpose of this module is to learn a better method of rounding than to a certain number of decimal places which ensures a certain level of accuracy in your measurement. This method is Significant Figures.## Help on this Topic:

**40,208,000,000,000 km**away

**147,390,000 km**away

For example if the distance from Dublin to Cork is given as 255.30296000 km

Then there are 8 significant digits.

The most significant is the 2 which represents Two hundred kilometres.

The least significant is the 6 which represents Six centimeters.

The first (or most) significant figure is the first non zero digit.

The last (or least) significant figure is the last non zero digit.

The most significant is of much greater importance or significance than the lease significant digit.

If the width of a hair is given as 0.0000176000 metres.

Then there are 3 significant digits given.

The most significant is the 1 representing TEN micrometers.

The lease significant is the 6 representing 600 nanometers.

Now the exercise is a little hard to see what is being asked so here is an example:

Complete the missing numbers from the table.

Seperate your answers with commas.

Number | Number corrected to 1 decimal place | Number corrected to 2 decimal places | Number corrected to 1 significant figure | Number corrected to 2 significant figures |

3.2454 | 3.2 | 3.25 | 3 | 3.2 |

18.6151 |