1. **Easy:** Convert 4500 to scientific notation. Answer: $4.5 \times 10^{3}$ 2. **Easy:** Write 0.0032 in scientific notation. Answer: $3.2 \times 10^{-3}$ 3. **Easy:** Express 120000 in scientific notation. Answer: $1.2 \times 10^{5}$ 4. **Easy:** Convert $7 \times 10^{4}$ to standard form. Answer: 70000 5. **Easy:** Write 0.00056 in scientific notation. Answer: $5.6 \times 10^{-4}$ 6. **Medium:** Multiply $(3 \times 10^{5})$ by $(2 \times 10^{3})$ and express the answer in scientific notation. Steps: 1. Multiply the coefficients: $3 \times 2 = 6$ 2. Add the exponents: $5 + 3 = 8$ 3. Combine: $6 \times 10^{8}$ Answer: $6 \times 10^{8}$ 7. **Medium:** Divide $(8 \times 10^{7})$ by $(4 \times 10^{2})$. Steps: 1. Divide coefficients: $8 \div 4 = 2$ 2. Subtract exponents: $7 - 2 = 5$ 3. Combine: $2 \times 10^{5}$ Answer: $2 \times 10^{5}$ 8. **Medium:** Add $5 \times 10^{3}$ and $3 \times 10^{4}$ (express answer in scientific notation). Steps: 1. Rewrite $5 \times 10^{3}$ as $0.5 \times 10^{4}$ to match powers of 10. 2. Add: $0.5 + 3 = 3.5$ 3. Final answer: $3.5 \times 10^{4}$ 9. **Medium:** Subtract $2.5 \times 10^{6}$ from $5 \times 10^{6}$. Steps: 1. Coefficients: $5 - 2.5 = 2.5$ 2. Powers of ten are the same so keep $10^{6}$. 3. Answer: $2.5 \times 10^{6}$ 10. **Medium:** Express $0.000098$ in scientific notation. Answer: $9.8 \times 10^{-5}$ 11. **Hard:** Multiply $(4.5 \times 10^{-3})$ by $(2 \times 10^{5})$. Steps: 1. Multiply coefficients: $4.5 \times 2 = 9$ 2. Add exponents: $-3 + 5 = 2$ 3. Result: $9 \times 10^{2}$ Answer: $9 \times 10^{2}$ 12. **Hard:** Divide $(7.2 \times 10^{8})$ by $(3 \times 10^{4})$. Steps: 1. Divide coefficients: $7.2 \div 3 = 2.4$ 2. Subtract exponents: $8 - 4 = 4$ 3. Combine: $2.4 \times 10^{4}$ Answer: $2.4 \times 10^{4}$ 13. **Hard:** Add $6.3 \times 10^{5}$ and $2.4 \times 10^{4}$ in scientific notation. Steps: 1. Rewrite $2.4 \times 10^{4}$ as $0.24 \times 10^{5}$. 2. Add coefficients: $6.3 + 0.24 = 6.54$ 3. Combine: $6.54 \times 10^{5}$ Answer: $6.54 \times 10^{5}$ 14. **Hard:** Subtract $1.2 \times 10^{-3}$ from $5.6 \times 10^{-3}$. Steps: 1. Coefficients: $5.6 - 1.2 = 4.4$ 2. Powers of ten are same so keep $10^{-3}$. 3. Answer: $4.4 \times 10^{-3}$ 15. **Hard:** Express 0.00000037 in scientific notation. Answer: $3.7 \times 10^{-7}$