Scientific Notation Calculator

Convert numbers to and from scientific notation, and add, subtract, multiply, divide or raise numbers in scientific notation – every step explained.

Result
25{,}000 = 2.5 \times 10^{4}

In scientific notation, \displaystyle 25{,}000 is \displaystyle 2.5 \times 10^{4}.

  • Decimal (ordinary) form: 25,000
  • E-notation: 2.5E+4 (calculators, Excel, programming)
  • Engineering notation: 25 × 10³ (the power is a multiple of 3)
  • Said aloud: two point five times ten to the power of four
  • Significant figures in the number you typed: 2 to 5 (the zeros at the end may or may not count)
  • Order of magnitude: \displaystyle 10^{4}

Step-by-step solution

The problem

\text{Write } 25{,}000 \text{ in scientific notation}
1

Find the coefficient

a = 2.5

Scientific notation is \displaystyle a \times 10^{n} with \displaystyle 1 \le a < 10. Put the decimal point just after the first non-zero digit (2); the zeros at the end only hold places, so they are left out.

2

Count the places the decimal point moves

  1. 25,000
  2. 2500
  3. 250
  4. 25
  5. 2.5

From \displaystyle 25{,}000 to \displaystyle 2.5 the decimal point moves 4 places to the left.

3

Choose the sign of the exponent

n = 4

The number is 10 or more, so the point moved left and the exponent is positive: each place left divides by 10, and \displaystyle 10^{4} multiplies it back.

4

Write it in scientific notation

25{,}000 = \textcolor{#0b5c56}{2.5 \times 10^{4}}

Check

2.5 \times 10^{4} = 2.5 \times 10{,}000 = 25{,}000 \;\checkmark

Multiply the coefficient by the power of ten to get back the number.

How to use the scientific notation calculator

  1. Choose the calculation: convert a number (either way), or multiply, divide, add, subtract or raise to a power.
  2. Type the number the way you would write it: 0.00052, 2500000, 2,500,000, 6.022e23, 3.2 × 10^5 (or 3.2x10^5, 3.2*10^-5) or 1.5 million.
  3. Pick how to give the answer: keep every digit, or round to a number of significant figures.
  4. You get the answer, the worked solution step by step (the decimal point moving one place at a time), a check, and the number in decimal form, E-notation and engineering notation.

What is scientific notation?

Scientific notation writes a number as a number between 1 and 10 multiplied by a power of ten:

a \times 10^{n}, \qquad 1 \le a < 10, \quad n \text{ a whole number}
  • a is the coefficient (also called the mantissa or significand). It has exactly one non-zero digit before the decimal point.
  • n is the exponent. It is positive for numbers of 10 or more, negative for numbers less than 1, and 0 for numbers from 1 to 10.

It makes very large and very small numbers short and easy to compare: the distance to the Sun, about 150,000,000 km, is 1.5 \times 10^{8} km, and the width of a red blood cell, about 0.000008 m, is 8 \times 10^{-6} m.

How to write a number in scientific notation

  1. Find the coefficient: put the decimal point just after the first non-zero digit. For 0.00052 that gives 5.2; for 2,500,000 it gives 2.5 (zeros at the end are only placeholders).
  2. Count the places the decimal point moved to get there.
  3. Choose the sign: if the point moved left (a big number) the exponent is positive; if it moved right (a number less than 1) the exponent is negative.
  4. Write coefficient × 10exponent, and check by multiplying back.

Example 1: 2,500,000. The decimal point moves 6 places to the left (2,500,000 → 250,000 → 25,000 → 2,500 → 250 → 25 → 2.5), so

2{,}500{,}000 = 2.5 \times 10^{6}

Example 2: 0.00052. The decimal point moves 4 places to the right (0.00052 → 0.0052 → 0.052 → 0.52 → 5.2), so the exponent is negative:

0.00052 = 5.2 \times 10^{-4}

How to convert scientific notation to a decimal number

Do the moves backwards: a positive exponent moves the decimal point to the right (the number gets bigger), a negative exponent moves it to the left (the number gets smaller). Fill empty places with zeros.

  • 3.2 \times 10^{5}: move the point 5 places right → 320,000.
  • 7.06 \times 10^{-3}: move the point 3 places left → 0.00706.
  • E-notation works the same way: 6.022E23 means 6.022 \times 10^{23}, and 1.6E-19 means 1.6 \times 10^{-19}.

Numbers in scientific notation

The numbers people look up most often. Select one to see the full working.

NumberScientific notationE-notation
101 \times 10^{1}1E+1
1001 \times 10^{2}1E+2
10001 \times 10^{3}1E+3
50005 \times 10^{3}5E+3
10,0001 \times 10^{4}1E+4
25,0002.5 \times 10^{4}2.5E+4
100,0001 \times 10^{5}1E+5
150,0001.5 \times 10^{5}1.5E+5
1,000,0001 \times 10^{6}1E+6
2,500,0002.5 \times 10^{6}2.5E+6
93,000,0009.3 \times 10^{7}9.3E+7
1,000,000,0001 \times 10^{9}1E+9
0.11 \times 10^{-1}1E-1
0.011 \times 10^{-2}1E-2
0.0011 \times 10^{-3}1E-3
0.0055 \times 10^{-3}5E-3
0.00011 \times 10^{-4}1E-4
0.000252.5 \times 10^{-4}2.5E-4
0.0000011 \times 10^{-6}1E-6
0.00000565.6 \times 10^{-6}5.6E-6

Famous numbers in scientific notation

QuantityValue
Speed of light2.998 \times 10^{8} m/s (299,792,458 m/s)
Avogadro's number6.022 \times 10^{23} per mole
Mass of the Earth5.972 \times 10^{24} kg
Distance from the Earth to the Sun1.496 \times 10^{11} m
World population (about 8 billion)8 \times 10^{9}
Charge of an electron1.602 \times 10^{-19} C
Mass of an electron9.109 \times 10^{-31} kg
Planck's constant6.626 \times 10^{-34} J·s
Width of a human hair (about 0.00008 m)8 \times 10^{-5} m

Multiplying and dividing in scientific notation

  • Multiply: multiply the coefficients and add the exponents. (3 \times 10^{4}) \times (5 \times 10^{6}) = 15 \times 10^{10} = 1.5 \times 10^{11}
  • Divide: divide the coefficients and subtract the exponents. (8 \times 10^{5}) \div (2 \times 10^{-3}) = 4 \times 10^{8}
  • Power: raise the coefficient to the power and multiply the exponents. (3 \times 10^{4})^{2} = 9 \times 10^{8}
  • If the new coefficient is 10 or more, move its decimal point left and add to the exponent; if it is less than 1, move it right and subtract.

Adding and subtracting in scientific notation

The coefficients can only be added or subtracted when the powers of ten are the same. Rewrite the number with the smaller exponent first:

1.375 \times 10^{4} + 2.548 \times 10^{2} = 1.375 \times 10^{4} + 0.02548 \times 10^{4} = 1.40048 \times 10^{4}

Significant figures

  • All non-zero digits count: 4.56 has 3 significant figures.
  • Zeros between non-zero digits count: 2.05 has 3.
  • Zeros in front never count: 0.0052 has 2.
  • Zeros at the end count after a decimal point (2.50 has 3), but in a whole number like 2,500,000 they may or may not. Scientific notation removes the doubt: 2.5 \times 10^{6} has 2, 2.500 \times 10^{6} has 4.
  • To round, look at the first digit you drop: 5 or more rounds up, less than 5 leaves the kept digits as they are.

Powers of ten and their names

PowerNumberNamePrefix
10^{12}1,000,000,000,000trilliontera (T)
10^{9}1,000,000,000billiongiga (G)
10^{7}10,000,000crore
10^{6}1,000,000millionmega (M)
10^{5}100,000lakh
10^{3}1,000thousandkilo (k)
10^{2}100hundredhecto (h)
10^{1}10tendeca (da)
10^{0}1one
10^{-1}0.1one tenthdeci (d)
10^{-2}0.01one hundredthcenti (c)
10^{-3}0.001one thousandthmilli (m)
10^{-6}0.000001one millionthmicro (µ)
10^{-9}0.000000001one billionthnano (n)

“Standard form” means different things

  • In the UK, India and many other countries, “standard form” is scientific notation: 2.5 × 106.
  • In the US, “standard form” usually means the ordinary way of writing a number: 2,500,000.
  • The answer shows both, clearly labelled, so you can use whichever your class or textbook means.

E-notation and engineering notation

  • E-notation is how calculators, spreadsheets and programming languages show scientific notation: 5.2E-4 = 5.2 \times 10^{-4}.
  • Engineering notation uses only powers that are multiples of 3, matching the prefixes kilo, mega, milli and micro: 0.00052 = 520 \times 10^{-6} (520 micro).

Converting between lakh, crore, million and billion? Use the number converter. To write a number in words, use number to words.

Frequently asked questions

How do you write a number in scientific notation?

Move the decimal point until one non-zero digit is in front of it – that is the coefficient. Count the places it moved: that number is the exponent, positive if the original number is 10 or more and negative if it is less than 1. For example 0.00052 = 5.2 × 10⁻⁴ and 2,500,000 = 2.5 × 10⁶.

How do you convert scientific notation to a normal number?

Move the decimal point by the exponent: to the right for a positive exponent, to the left for a negative one, filling empty places with zeros. 3.2 × 10⁵ = 320,000 and 7.06 × 10⁻³ = 0.00706.

How do you multiply numbers in scientific notation?

Multiply the coefficients and add the exponents, then adjust if the coefficient is 10 or more: (3 × 10⁴)(5 × 10⁶) = 15 × 10¹⁰ = 1.5 × 10¹¹.

How do you divide numbers in scientific notation?

Divide the coefficients and subtract the exponents: (8 × 10⁵) ÷ (2 × 10⁻³) = 4 × 10⁸. If the coefficient comes out less than 1, move its decimal point right and subtract from the exponent.

How do you add or subtract in scientific notation?

First make the powers of ten the same by rewriting the number with the smaller exponent, then add or subtract the coefficients and keep the power: 1.375 × 10⁴ + 2.548 × 10² = 1.375 × 10⁴ + 0.02548 × 10⁴ = 1.40048 × 10⁴.

What does E mean on a calculator?

E stands for “times ten to the power of”. 6.022E23 means 6.022 × 10²³ and 1.6E-19 means 1.6 × 10⁻¹⁹.

Is 10 × 10³ in scientific notation?

No – the coefficient must be at least 1 and less than 10. 10 × 10³ is written 1 × 10⁴.

What is 0.0001 in scientific notation?

0.0001 = 1 × 10⁻⁴: the decimal point moves 4 places to the right to reach 1.