Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Standard form, also known as scientific notation, is a method used to express very large numbers in a compact and readable format. Visually, a long string of digits like is condensed into a shorter expression involving a decimal and a power of .
Any number in standard form is written as the product of a decimal number and a power of , expressed as . In this structure, is a terminating decimal such that , meaning there is exactly one non-zero digit to the left of the decimal point.
To convert a large number to standard form, we move the decimal point to the left. For every place the decimal point moves, the power of increases by . You can visualize the decimal point 'jumping' over digits from right to left until it rests immediately after the first non-zero digit.
The exponent in the power represents the total number of places the decimal point has shifted. For instance, in the number , we imagine the decimal at the end () and move it places left to get , resulting in .
Standard form is highly effective for comparing the magnitude of very large numbers. When comparing two numbers, first look at the exponent of ; the number with the larger exponent is always larger. If the exponents are equal, you then compare the decimal coefficients ().
Powers of represent the place value system in a simplified way. For example, , , and . Visually, the exponent corresponds exactly to the number of zeros following the digit in the expanded form of the power.
📐Formulae
Standard Form:
Range of coefficient:
Power of ten:
Large number expansion:
💡Examples
Problem 1:
Express the number in standard form.
Solution:
Step 1: Locate the decimal point. In , the decimal point is at the end: . \ Step 2: Move the decimal point to the left until only one digit () remains to the left of the decimal. \ Step 3: Count the number of places the decimal moved. Here, it moves places to the left to become . \ Step 4: Write the number as a product of the new decimal and raised to the power of the count. \ Final Answer:
Explanation:
The decimal was moved places to the left to ensure the coefficient (which is ) falls between and .
Problem 2:
The distance between the Earth and the Sun is approximately km. Express this distance in standard form.
Solution:
Step 1: The decimal point is at the end of . \ Step 2: Shift the decimal point to the left to sit between the digits and . \ Step 3: Count the shifts: the decimal moves places (). \ Step 4: Express the result as . \ Final Answer: km
Explanation:
Moving the decimal places to the left results in a coefficient of . Since we moved places, the exponent for the base is .