1. **Problem:** Select each equation that the number $10^3$ will make true. 2. **Understanding the problem:** $10^3 = 1000$. We need to find which unit conversions equal 1000. 3. **Recall unit conversions:** - 1 km = 1000 m - 1 m = 100 cm - 1 cm = 10 mm - 1 m = 10 dm - 1 mm = 0.001 m 4. **Check each equation:** - $? \text{ km} = 1 \text{ mm}$ means $x \times 1000 \text{ m} = 0.001 \text{ m}$, so $x = 0.000001$, not $10^3$. - $? \text{ mm} = 1 \text{ m}$ means $x \times 0.001 \text{ m} = 1 \text{ m}$, so $x = 1000 = 10^3$ (True). - $? \text{ cm} = 1 \text{ m}$ means $x \times 0.01 \text{ m} = 1 \text{ m}$, so $x = 100$, not $10^3$. - $? \text{ m} = 1 \text{ km}$ means $x \times 1 \text{ m} = 1000 \text{ m}$, so $x = 1000 = 10^3$ (True). - $? \text{ dm} = 1 \text{ m}$ means $x \times 0.1 \text{ m} = 1 \text{ m}$, so $x = 10$, not $10^3$. 5. **Final answer:** The equations that $10^3$ makes true are: - $10^3 \text{ mm} = 1 \text{ m}$ - $10^3 \text{ m} = 1 \text{ km}$