Edexcel Mathematics (4XMAF) -Unit 2 - 1.9 Standard Form- Study Notes- New Syllabus
Edexcel Mathematics (4XMAF) -Unit 2 – 1.9 Standard Form- Study Notes- New syllabus
Edexcel Mathematics (4XMAF) -Unit 2 – 1.9 Standard Form- Study Notes -Edexcel iGCSE Mathematics – per latest Syllabus.
Key Concepts:
A calculate with and interpret numbers in the form a × 10ⁿ where n is an integer and 1 ≤ a < 10
150000000 = 1.5 × 10⁸
Edexcel iGCSE Mathematics -Concise Summary Notes- All Topics
Standard Form (Scientific Notation)
Very large or very small numbers are often written in standard form.
A number is written as:
\( a \times 10^n \)
where:
\( 1 \le a < 10 \)
\( n \) is an integer (positive or negative)
Example
\( 150\,000\,000 = 1.5 \times 10^8 \)
How to Convert to Standard Form
Move the decimal point so the first number is between 1 and 10.
• Moving left → positive power
• Moving right → negative power
Converting Back
Multiply by \( 10^n \).
- Positive power → move decimal right
- Negative power → move decimal left
Example 1:
Write \( 4\,500\,000 \) in standard form.
▶️ Answer/Explanation
Move decimal 6 places left:
\( 4.5 \times 10^6 \)
Conclusion: \( 4.5 \times 10^6 \).
Example 2:
Write \( 0.00072 \) in standard form.
▶️ Answer/Explanation
Move decimal 4 places right:
\( 7.2 \times 10^{-4} \)
Conclusion: \( 7.2 \times 10^{-4} \).
Example 3:
Write \( 3.2 \times 10^5 \) as an ordinary number.
▶️ Answer/Explanation
Move decimal 5 places right:
\( 320000 \)
Conclusion: \( 320000 \).