Recognise and Write Numbers in Standard Form
Distance in outer space, such as the distance between two planets in our Solar System, can be measured in km and sometimes in light-years. One light-year is the distance travelled by light in one year. One light-year is equal to 9 500 000 000 000 km or equal to 9.5 trillion kilometres.
In scientific information, very big or very small numbers such as light-year are commonly written in standard form. Standard form is widely used in the field of science, engineering, astronomy and so on.
Standard form is a way to write a single number in the form;
A x 10n , where 1 ≤ A ≤ 10 and n is an integer.
For example, one light-year is approximately 9 500 000 000 000 km. This value can be written as 9.5 x 1012 km or depending on the number of significant figures required.
How do we change a single number to standard form? Remember these rules
- Numbers with value more than 1 will be given positive index, an
- Numbers with value less than 1 will be given negative index, a-n
Here we show you some examples how we changing single numbers to standard form and vice versa.
- 534 000 = 5.34 x 105
- 0.000534 = 5.34 x 10-4
- 2.763 x 104 = 27 630
- 2.763 x 10-4 = 0.0 002 763
Now you understand how we changing single numbers to standard form and vice versa.
Why must we learn standard form?
We use measurement in many situations in our daily life. Examples of frequently used measurements are length, distance, mass, temperature, area and even speed. Standard form makes it easier to write very big and very small numbers in a form that is simple and easy to understand.