Standard form - EdexcelConverting from standard form

Calculations with very big or small numbers can be made easier by converting numbers in and out of standard form.

Part ofMathsNumber

Converting from standard form

To convert a number in to an ordinary number, simply do the multiplication.

Examples

\(1.34 \times 10^3\) is 1,340, since \(1.34 \times 10 \times 10 \times 10 = 1,340\).

\(4.78 \times 10^{-3}\) is 0.00478, as \(4.78 \times 0.001 = 0.00478\).

Question

Write the following as ordinary numbers:

  • \(2.99 \times 10^7\)
  • \(1.36 \times 10^{-7}\)

This process can also be sped up by considering where the first digit is compared to the units column.

Examples

\(3.51 \times 10^5\) = 351,000 because the 3 moves 5 places away from the units column. Two places are filled by 5 and 1. Put zeros in the other three places.

\(3.08 \times 10^{-4}\) = 0.000308 because the 3 moves 4 places away from the units column. Put zeros in the other 3 places. Focus on the 3, not the 8.

Question

Complete the table with the measurements in standard form.

ExampleNumber (metres)Standard form
Height of a skyscraper300
Length of a virus0.0000003
Size of a galaxy300,000,000,000,000,000,000
Height of a mountain3,000
Nucleus of an atom0.00000000000003
ExampleHeight of a skyscraper
Number (metres)300
Standard form
ExampleLength of a virus
Number (metres)0.0000003
Standard form
ExampleSize of a galaxy
Number (metres)300,000,000,000,000,000,000
Standard form
ExampleHeight of a mountain
Number (metres)3,000
Standard form
ExampleNucleus of an atom
Number (metres)0.00000000000003
Standard form