Let's analyze each statement in the image to determine which two are correct.

A) $315 \, \text{km} = 3.15 \times 10^6 \, \text{cm}$

• To check this, we convert 315 km to cm: $315 \, \text{km} = 315 \times 10^3 \, \text{m} = 315 \times 10^3 \times 10^2 \, \text{cm} = 3.15 \times 10^7 \, \text{cm}$ The given value is $3.15 \times 10^6 \, \text{cm}$, which is incorrect.

B) $0.0485 \, \text{m} = 4.85 \times 10^1 \, \text{mm}$

• To check this, we convert 0.0485 m to mm: $0.0485 \, \text{m} = 0.0485 \times 10^3 \, \text{mm} = 48.5 \, \text{mm} = 4.85 \times 10^1 \, \text{mm}$ This is correct.

C) $30,451 \, \text{t} = 3.0451 \times 10^9 \, \text{g}$

• To check this, we convert 30,451 t to grams: $30,451 \, \text{t} = 30,451 \times 10^6 \, \text{g} = 3.0451 \times 10^{10} \, \text{g}$ The given value is $3.0451 \times 10^9 \, \text{g}$, which is incorrect.

D) $0.043 \, \text{cm}^3 = 4.3 \times 10^{-8} \, \text{m}^3$

• To check this, we convert 0.043 cm³ to m³: $0.043 \, \text{cm}^3 = 0.043 \times 10^{-6} \, \text{m}^3 = 4.3 \times 10^{-8} \, \text{m}^3$ This is correct.

E) $439 \, \text{ha} = 4.39 \times 10^4 \, \text{m}^2$

• To check this, we convert 439 ha to m²: $439 \, \text{ha} = 439 \times 10^4 \, \text{m}^2 = 4.39 \times 10^6 \, \text{m}^2$ The given value is $4.39 \times 10^4 \, \text{m}^2$, which is incorrect.

Conclusion:

The correct answers are B and D.

Would you like any more details or have any further questions?

Here are 5 related questions to explore:

1. How do you convert units between metric system measurements?
2. Why is scientific notation useful in expressing large or small quantities?
3. What are the steps to convert cubic centimeters (cm³) to cubic meters (m³)?
4. How is the conversion factor between hectares (ha) and square meters (m²) derived?
5. Can you explain the process of converting tons to grams in more detail?

Tip: Always double-check your units when converting between different metric measurements to ensure the powers of ten are correctly applied