Scientific notation
The mass of the Earth is $5\,970\,000\,000\,000\,000\,000\,000\,000$ kg. The mass of an oxygen atom is $0{,}0000000000000000000000266$ g. No scientist writes this with all those zeros: they use powers of 10. It is the standard language for working with astronomical or subatomic scales without losing count of the digits.
What scientific notation is
Travel across the scales of the universe, from the atom to the galaxy, all on the same line:
Express the following integers and terminating decimals in standard form: a) $450\,000\,000$ b) $32\,500$ c) $8\,400\,000\,000\,000$
Express the following integers and terminating decimals in standard form:
- a) $450\,000\,000$
- b) $32\,500$
- c) $8\,400\,000\,000\,000$
Express the following small decimal numbers in standard form: a) $0,0000045$ b) $0,00000000128$ c) $0,003$
Express the following small decimal numbers in standard form:
- a) $0,0000045$
- b) $0,00000000128$
- c) $0,003$
Converting between scientific notation and decimal form
The exponent counts how many places the decimal point moves.
Write out in full the following numbers given in standard form: a) $3,14 \cdot 10^6$ b) $8,05 \cdot 10^9$ c) $1,002 \cdot 10^4$
Write out in full the following numbers given in standard form:
- a) $3,14 \cdot 10^6$
- b) $8,05 \cdot 10^9$
- c) $1,002 \cdot 10^4$
Write the following numbers given in standard form in decimal form: a) $5,2 \cdot 10^{-5}$ b) $1,07 \cdot 10^{-8}$ c) $9,9 \cdot 10^{-3}$
Write the following numbers given in standard form in decimal form:
- a) $5,2 \cdot 10^{-5}$
- b) $1,07 \cdot 10^{-8}$
- c) $9,9 \cdot 10^{-3}$
Comparing and ordering
The exponent comes first. The mantissas are compared only if the exponents are the same.
Order the following numbers from smallest to largest, having first expressed them in standard form (with a single non-zero digit before the decimal point):…
Order the following numbers from smallest to largest, having first expressed them in standard form (with a single non-zero digit before the decimal point):
$A = 0,0034 \cdot 10^8$
$B = 450 \cdot 10^3$
$C = 3,2 \cdot 10^5$
$D = 0,05 \cdot 10^7$
Operating in scientific notation
Multiplying and dividing: the mantissas and the powers of 10 are dealt with separately, adding or subtracting the exponents; at the end, adjust the mantissa if it falls outside $[1, 10)$.
Adding and subtracting: the powers of 10 must be the same; if they are not, make them equal first.
Carry out the following multiplications and give the answer in standard form: a) $(3 \cdot 10^4) \cdot (2 \cdot 10^5)$ b) $(4 \cdot 10^{-3}) \cdot (2 \cdot 10^8)$
Carry out the following multiplications and give the answer in standard form:
- a) $(3 \cdot 10^4) \cdot (2 \cdot 10^5)$
- b) $(4 \cdot 10^{-3}) \cdot (2 \cdot 10^8)$
The mean distance from the Earth to the Sun is about $149\,600\,000$ km and the speed of light in a vacuum is approximately $300\,000$ km/s. Express both quantities in…
The mean distance from the Earth to the Sun is about $149\,600\,000$ km and the speed of light in a vacuum is approximately $300\,000$ km/s. Express both quantities in standard form and calculate how many seconds it takes for light from the Sun to reach the Earth.
The law of universal gravitation states that the gravitational force between two masses $m_1$ and $m_2$ separated by a distance $d$ is…
The law of universal gravitation states that the gravitational force between two masses $m_1$ and $m_2$ separated by a distance $d$ is $F = G \cdot \frac{m_1 \cdot m_2}{d^2}$, where $G = 6,67 \cdot 10^{-11} \text{ N}\cdot\text{m}^2/\text{kg}^2$. Calculate the force of attraction between the Earth ($m_1 = 5,97 \cdot 10^{24}$ kg) and the Moon ($m_2 = 7,35 \cdot 10^{22}$ kg), given that the mean distance between their centres is $3,84 \cdot 10^8$ m. Give the answer in standard form to three significant figures.
Back to the beginning: The mass of the Earth in scientific notation is $5{,}97 \cdot 10^{24}$ kg and the mass of an oxygen atom is $2{,}66 \cdot 10^{-23}$ g.