Scientific notation is a compact way of writing very large or very small numbers.

Instead of writing many zeros, scientific notation expresses a number using a coefficient multiplied by a power of 10.

In Python, scientific notation is written using the letter e or E.

The general form is:

coefficienteexponent

For example:

• 3.5e4 means 3.5 × 10⁴
• 2.1e-3 means 2.1 × 10⁻³

Scientific notation is commonly used in science, engineering, electronics, and mathematics where extremely large or very small values are frequently encountered.

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Syntax #

variable_name = coefficienteexponent

Components #

Component	Description
variable_name	Name of the variable.
coefficient	A decimal number.
e or E	Indicates “multiply by 10 raised to the power”.
exponent	Integer exponent that determines how many places the decimal point moves.

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Example 1: Positive Exponent #

main.py

number = 3.5e4

print(number)
print(type(number))

Output #

35000.0
<class 'float'>

Explanation #

• 3.5e4 means 3.5 × 10⁴.
• The decimal point moves four places to the right.
• Scientific notation always produces a floating-point value.

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Example 2: Negative Exponent #

main.py

number = 2.5e-3

print(number)

Output #

0.0025

Explanation #

• 2.5e-3 means 2.5 × 10⁻³.
• The decimal point moves three places to the left.
• This notation is useful for representing very small numbers.

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Example 3: Using Uppercase E #

main.py

number = 7.2E5

print(number)

Output #

720000.0

Explanation #

• Python accepts both lowercase e and uppercase E.
• Both represent scientific notation.
• The stored value is identical.

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Example 4: Checking the Data Type #

main.py

number = 9e2

print(number)
print(type(number))

Output #

900.0
<class 'float'>

Explanation #

• Even though the result is a whole number (900), Python stores it as a floating-point number because scientific notation always creates a float.

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Example 5: Scientific Notation in Calculations #

main.py

distance = 1.5e6
time = 2

speed = distance / time

print(speed)

Output #

750000.0

Explanation #

• Scientific notation can be used just like any other numeric value.
• Python performs arithmetic operations normally.
• The result is a floating-point number.

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Example 6: Very Small Scientific Value #

main.py

charge = 1.6e-19

print(charge)

Output #

1.6e-19

Explanation #

• Scientific notation is especially useful for representing extremely small values.
• Python automatically displays the value using exponential notation.

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Example 7: Converting Scientific Notation to Integer #

main.py

number = int(5e3)

print(number)
print(type(number))

Output #

5000
<class 'int'>

Explanation #

• 5e3 is initially stored as a floating-point value.
• The int() function converts it into an integer.
• After conversion, the data type becomes int.

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Example 8: Scientific Notation in Expressions #

main.py

result = 2e3 + 5e2

print(result)

Output #

2500.0

Explanation #

• 2e3 represents 2000.0.
• 5e2 represents 500.0.
• Python adds the two floating-point values.

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Example 9: Comparing Scientific Notation #

main.py

print(1e3 == 1000)

Output #

True

Explanation #

• 1e3 represents 1000.0.
• Python compares 1000.0 with 1000.
• Since the numeric values are equal, the result is True.

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Example 10: Scientific Notation from User Input #

main.py

number = float(input("Enter a number in scientific notation: "))

print(number)

Sample Input #

6.02e23

Output #

6.02e+23

Explanation #

• The user enters a number in scientific notation.
• float() converts the input string into a floating-point value.
• Python prints the equivalent floating-point number.

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Common Mistakes #

1. Forgetting the Exponent #

Incorrect

number = 2.5e

Output #

SyntaxError: invalid decimal literal

Reason

Scientific notation requires an exponent after e or E.

Correct

number = 2.5e3

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2. Assuming Scientific Notation Produces an Integer #

Incorrect

number = 5e2

print(type(number))

Incorrect Expectation #

<class 'int'>

Actual Output #

<class 'float'>

Reason

Scientific notation always creates a floating-point value.

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3. Using Multiple Decimal Points #

Incorrect

number = 2.5.3e4

Output #

SyntaxError: invalid syntax

Reason

A numeric literal can contain only one decimal point.

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4. Writing Spaces Inside Scientific Notation #

Incorrect

number = 3.5 e4

Output #

SyntaxError: invalid syntax

Reason

There must be no spaces between the coefficient, e, and the exponent.

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Best Practices #

• Use scientific notation for extremely large or very small numbers.
• Use lowercase e consistently for better readability.
• Remember that scientific notation values are stored as floating-point numbers.
• Use int() if an integer value is required after computation.
• Use meaningful variable names when storing scientific values.

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Key Points to Remember #

• Scientific notation provides a compact way to write very large or very small numbers.
• Python uses e or E to represent powers of 10.
• Positive exponents move the decimal point to the right.
• Negative exponents move the decimal point to the left.
• Scientific notation always produces a value of type float.
• Scientific notation values can participate in arithmetic operations like any other numeric values.
• Both lowercase e and uppercase E are valid in Python.