Scientific notation

Convert a number to scientific (exponential) notation and back.

Co je scientific notation

Scientific (exponential) notation expresses a number as a × 10ⁿ, where a is between 1 and 10 and n is an integer. It makes very large and very small numbers easy to write.

Where it is used in practice

  • Physics and astronomy: the Earth–Sun distance is 1.496 × 10¹¹ m.
  • Chemistry: Avogadro’s constant is 6.022 × 10²³ particles per mole.
  • Electronics and IT: file sizes, frequencies, chip dimensions.

Good to know

A positive exponent moves the decimal point right (large numbers), a negative one left (small numbers). 3 × 10⁻⁴ = 0.0003.

Rules of exponents

When working with powers it helps to know the basic rules, which always hold:

xⁿ · xᵖ = xⁿ⁺ᵖ   (product – add the exponents)
xⁿ ÷ xᵖ = xⁿ⁻ᵖ   (quotient – subtract the exponents)
(xⁿ)ᵖ = xⁿ·ᵖ   (power of a power – multiply)
x⁻ⁿ = 1 / xⁿ   (negative exponent)
x^(1/n) = ⁿ√x   (root as a power)

In detail with examples: rules of exponents.

Tip: very large numbers are shown in shortened form – use scientific notation.