Scientific Notation

7 min read · Updated September 26, 2026 · by the SolveCalcPro editorial team

Scientists deal with numbers as huge as the number of atoms in a gram of matter and as tiny as the width of a virus. Writing all those zeros is slow and error-prone. Scientific notation packs any number into a coefficient between 1 and 10 times a power of ten.

Writing a number in scientific notation

Move the decimal point until one non-zero digit is in front, then count the moves. 45,000,000 becomes 4.5 × 10⁷ (moved seven places left). 0.00072 becomes 7.2 × 10⁻⁴ (moved four places right, so the exponent is negative). Check with the scientific notation converter.

Converting back to standard form

Move the decimal point the number of places the exponent says: right for positive, left for negative. 3.2 × 10⁵ = 320,000 and 6.5 × 10⁻³ = 0.0065.

Multiplying and dividing

Multiply the coefficients and add the exponents: (3 × 10⁴)(2 × 10⁵) = 6 × 10⁹. Divide the coefficients and subtract the exponents: (8 × 10⁶) ÷ (2 × 10²) = 4 × 10⁴.

Adding and subtracting

First give both numbers the same exponent. 2.5 × 10³ + 3 × 10² = 2.5 × 10³ + 0.3 × 10³ = 2.8 × 10³ (that is 2,500 + 300 = 2,800).

Fixing the coefficient

If a calculation leaves a coefficient outside 1 to 10, adjust it. 12 × 10³ = 1.2 × 10⁴, and 0.6 × 10⁵ = 6 × 10⁴.

Examples from science

Quantity	Scientific notation
Speed of light (m/s, rounded)	3.00 × 10⁸
Avogadro’s number	6.022 × 10²³
Diameter of a hydrogen atom (m, approx.)	1 × 10⁻¹⁰

On a calculator, use the EXP or EE key, or type 3.2e5. In our scientific calculator, try 3e8*2.

Practice questions

Test yourself, then tap to check. Answers are calculated by the tools linked below.

Write 45,000,000 in scientific notation.
Show answer
Scientific notation: 4.5 × 10^7
Calculate 7^4.
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7^4: 2,401
Round 7.8449 to 2 decimal places.
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Rounded to 2 decimal places: 7.84