Express 0.00045 in scientific notation.

A 4.5 × 10⁻³

B 4.5 × 10⁻⁴

C 45 × 10⁻⁵

D 0.45 × 10⁻³

✓ Correct Answer: Option B

0.00045 = 4.5 × 10⁻⁴ (decimal moves 4 places right).

💡 Why is B) the correct answer?

The correct answer to the question "Express 0.00045 in scientific notation." is Option B: 4.5 × 10⁻⁴.

The other options — A) 4.5 × 10⁻³, C) 45 × 10⁻⁵, D) 0.45 × 10⁻³ — are incorrect for this ACT Exam Prep question. As explained above: 0.00045 = 4.5 × 10⁻⁴ (decimal moves 4 places right).

📚 About This ACT Exam Prep Practice Question

This 1-level ACT Exam Prep question from the Mathematics topic is part of BrainForge Quiz's free exam preparation library. Each question includes the correct answer and a detailed explanation to help you understand the underlying concept, not just memorize the answer.

How to use this page: Read the question above, consider all four options (A through D), then check the highlighted correct answer and explanation. For active timed practice, start a free ACT Exam Prep practice test or use flashcards for spaced repetition review.

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Express 0.00045 in scientific notation.

✓ Correct Answer: Option B

📚 About This ACT Exam Prep Practice Question

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