Question 276 of 480
What is the result of simplifying the expression \( (3 \times 10^4) \times (2 \times 10^3) \) in standard form?
- \( 6 \times 10^7 \)
- \( 6 \times 10^8 \)
- \( 5.1 \times 10^8 \)
- \( 6 \times 10^6 \)
Correct Answer:
B
Explanation
To simplify the expression \( (3 \times 10^4) \times (2 \times 10^3) \) in standard form, we will follow a step-by-step approach.
### Step 1: Understand the Components
The expression consists of two parts:
- \( 3 \times 10^4 \)
- \( 2 \times 10^3 \)
Here, \( 3 \) and \( 2 \) are the coefficients, while \( 10^4 \) and \( 10^3 \) are the powers of ten.
### Step 2: Multiply the Coefficients
First, we multiply the coefficients:
\[
3 \times 2 = 6
\]
### Step 3: Add the Exponents
Next, we need to multiply the powers of ten. When multiplying numbers in scientific notation, we add the exponents:
\[
10^4 \times 10^3 = 10^{4+3} = 10^7
\]
### Step 4: Combine the Results
Now, we combine the results from Steps 2 and 3:
\[
(3 \times 10^4) \times (2 \times 10^3) = 6 \times 10^7
\]
### Final Result
Thus, the simplified expression in standard form is:
\[
6 \times 10^7
\]
### Conclusion
The correct option is **A. \( 6 \times 10^7 \)**.
### Explanation of Other Options
- **B. \( 6 \times 10^8 \)**: This option is incorrect because it suggests that we added the exponents incorrectly (4 + 3 = 8 instead of 7).
- **C. \( 5.1 \times 10^8 \)**: This option is incorrect as it not only has the wrong exponent but also an incorrect coefficient. The multiplication of the coefficients (3 and 2) gives 6, not 5.1.
- **D. \( 6 \times 10^6 \)**: This option is incorrect because it suggests that the exponent was reduced instead of correctly adding them. The correct exponent is 7, not 6.
### Common Pitfalls
- **Forgetting to add the exponents**: When multiplying powers of ten, always remember to add the exponents.
- **Incorrectly multiplying coefficients**: Ensure that you multiply the coefficients accurately.
- **Misinterpreting standard form**: Standard form requires the coefficient to be between 1 and 10, which is satisfied in this case.
### Revision Summary
- Multiply the coefficients: \( 3 \times 2 = 6 \).
- Add the exponents: \( 10^4 \times 10^3 = 10^{7} \).
- Combine results: \( 6 \times 10^7 \) is the final answer.
- The correct option is **A. \( 6 \times 10^7 \)**.