1. **Problem statement:** Estimate the answers for the following calculations and write the results with 3 significant figures. 2. **Estimation rules:** To estimate, round each number to a convenient value that makes mental calculation easier, then perform the operation. 3. **Part i) Estimate $74356 \times 29754$:** - Round $74356$ to $74000$ (3 significant figures). - Round $29754$ to $30000$ (3 significant figures). - Multiply the rounded numbers: $$74000 \times 30000 = 2.22 \times 10^{9}$$ - Write in 3 significant figures: $2.22 \times 10^{9}$. 4. **Part ii) Estimate $86789 \div 4456$:** - Round $86789$ to $87000$ (3 significant figures). - Round $4456$ to $4500$ (3 significant figures). - Divide the rounded numbers: $$\frac{87000}{4500} = 19.333...$$ - Write in 3 significant figures: $19.3$. **Final answers:** - i) $2.22 \times 10^{9}$ - ii) $19.3$