Grade 10 → Number Systems → Exponents and Radicals ↓
Scientific Notation
Scientific notation is a method of writing very large or very small numbers in a concise form. This form makes it easier to perform calculations and conceptualize extreme values. Scientific notation expresses numbers as multiples of two factors: the number between 1 and 10 and the power of ten. It is widely used in mathematics, physics, engineering, and other sciences.
Understanding scientific notation
Scientific notation is expressed as follows:
a × 10^n
Where:
a
is a number that is greater than or equal to 1 and less than 10.n
is an integer, which can be positive, negative, or zero.
For example, the number 3000 can be written in scientific notation like this:
3 × 10^3
Why use scientific notation?
Scientific notation is especially useful when working with very large numbers such as the speed of light (about 299,792,458 meters per second) or very small numbers such as the mass of an electron (about 0.00000000000000000000000000000091093822 kilograms).
Writing these numbers in decimal form is cumbersome and even more challenging to calculate. Scientific notation reduces this complexity and provides a convenient way to perform multiplication and division, especially using a calculator or computer.
How to convert to scientific notation
Follow these simple steps to convert a number to scientific notation:
- Move the decimal point in the number so that only the first non-zero digit remains to the left of the decimal point.
For example, to convert 12300 to scientific notation:1.23
- Count the number of places,
p
, that you moved the decimal point.
In this example, you moved the decimal point 4 places to the left. - Express the original number as the product of
a
and the powerp
of 10.1.23 × 10^4
Examples of scientific notation
Let us work through some examples to understand this concept better:
Example 1: Large numbers
Convert 5,800,000 to scientific notation:
- Move the decimal point so that there is only one digit to the left:
5.8
- Count the moves: it's 6 moves to the left.
- Write it like this
5.8 × 10^6
Example 2: Small number
Convert 0.00045 to scientific notation:
- Move the decimal point so that there is only one digit to the left:
4.5
- Count the moves: It's 4 moves to the right.
- Write it like this
4.5 × 10^-4
Operations with scientific notation
When performing operations such as multiplication and division with numbers in scientific notation, you can take advantage of the properties of exponents:
Multiplication
When multiplying numbers in scientific notation:
(a × 10^n) × (b × 10^m) = (a × b) × 10^(n+m)
Example:
Multiply (3 × 10^4)
and (2 × 10^2)
:
(3 × 10^4) × (2 × 10^2) = 6 × 10^(4+2) = 6 × 10^6
Division
When dividing numbers in scientific notation:
(a × 10^n) ÷ (b × 10^m) = (a ÷ b) × 10^(n-m)
Example:
Divide (6 × 10^6)
by (2 × 10^2)
:
(6 × 10^6) ÷ (2 × 10^2) = 3 × 10^(6-2) = 3 × 10^4
Additional examples
Here are some more conversions and calculations with scientific notation to help you practice:
Conversion to scientific notation
- 0.00567 in scientific notation
5.67 × 10^-3
- 987,000 in scientific notation is
9.87 × 10^5
- 0.0000002085 in scientific notation is
2.085 × 10^-7
Performing the calculation
Calculate the result using scientific notation:
- (2.5 × 10^5) + (3.5 × 10^5) = ...
Align exponents: (2.5 + 3.5) × 10^5 = 6.0 × 10^5
- (6.3 × 10^7) × (4.2 × 10^-3) = ...
(6.3 × 4.2) × 10^(7 – 3) = 26.46 × 10^4 = 2.646 × 10^5
Practicing with exponents and radicals
Scientific notation often involves operations with exponents. Let's explore these with practical examples:
Exponential
It is extremely important to understand and use powers of ten in scientific notation:
- 10^3 means 10 × 10 × 10 = 1,000
- 10^-4 means 1/(10 × 10 × 10 × 10) = 0.0001
Radicals
Scientific notation can simplify roots, especially square roots and higher-order roots:
Example: Simplifying the square root of 2,500,000
2,500,000 = 2.5 × 10^6 √(2.5 × 10^6) = √2.5 × √10^6 = 1.58 × 10^3
Visual example: powers of ten
Key takeaways
- Scientific notation makes it simple to work with large and small numbers.
- It is expressed as
a × 10^n
. - Exponents in scientific notation help multiply and divide numbers effectively.
- For practice, make sure you're comfortable converting and working with scientific notation.
Conclusion
Scientific notation is a powerful tool for efficiently handling exceptionally large or small numbers in math and science. Mastering scientific notation ensures better understanding in dealing with data that requires precision or concerns high magnitude. Extensive practice on performing conversions and calculations with scientific notation will lead to greater confidence and competence in applications involving complex calculations.