**Standard Form** is a way of writing very small and very large numbers. It is written in two parts: the first part is a decimal number between 1 and 10, and the second part is a power of 10. An example of a number written in standard form is 3.44 x 10^{3}.

To turn a number written in standard form into a normal number, multiply the two parts of the standard form together:

3.44 x 10^{3}

= 3.44 x 1000 (as 10^{3} is 1000)

= 3440

To turn a normal number into standard form, determine the decimal number that will be between 1 and 10:

taking 295,000 as an example

2.95 is the decimal number between 1 and 10.

Work out what power of 10 will be needed to multiply 2.95 to make 295,000

2.95 needs to be multiplied by 100,000 = 10^{5}

The standard form of 295,000 is 2.95 x 10^{5}.

The sun, on average, is 92 960 000 miles away from the earth. Write this number in standard form.

92,960,000 = 9.296 x 10,000,000, therefore 9.296 x 10^{7}.

Answer: 9.296 x 10^{7}

The moon is 3.84 x 10^{5} kilometres from the earth. Write that as a normal number.

3.84 x 10^{5}

= 3.84 x 100,000

= 384,000 km

Answer: 384,000 km

See also Calculating with Indices

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