Standard Form

Summary and Exam Tips for Standard Form

Standard Form is a subtopic of Numbers, which falls under the subject Mathematics in the IB MYP curriculum. In standard form, a number is expressed as $A \times 10^n$, where $A$ is a number between 1 and 10, and $n$ is a whole number indicating the number of places the decimal point moves. For example, $3.2 \times 10^6$ is in standard form.

To convert a standard form into a large number, such as $4.2 \times 10^5$, move the decimal point 5 places to the right, resulting in 420,000. Conversely, to convert a small number like $2.8 \times 10^{-4}$, move the decimal point 4 places to the left, resulting in 0.00028.

When writing large numbers in standard form, such as 56,700,000, move the decimal point left until the number is between 1 and 10, resulting in $5.67 \times 10^7$. For small numbers like 0.0000099, move the decimal point right, resulting in $9.9 \times 10^{-6}$.

Exam Tips

• Understand the Basics: Ensure you know that $A$ must be between 1 and 10, and $n$ is the number of decimal places moved.
• Practice Conversions: Regularly practice converting between standard form and regular numbers to build confidence.
• Decimal Movement: Remember that moving the decimal to the right increases $n$, while moving it to the left decreases $n$.
• Check Your Work: After converting, double-check that $A$ is correctly between 1 and 10.
• Use Examples: Refer to examples like $4.2 \times 10^5 = 420,000$ to guide your understanding.