9. Use Structure \( A \) warehouse has 9 crates Each crate has 20 boxes of cereal. How many boxes of cereal does the warehous have? Explain how to use properties to solve the problem.

To solve the problem of how many boxes of cereal the warehouse has, we can follow these steps: 1. **Identify the known quantities:** - The number of crates in the warehouse: \( C = 9 \) - The number of boxes of cereal in each crate: \( B = 20 \) 2. **Determine the total number of boxes of cereal:** - To find the total number of boxes of cereal in the warehouse, we need to multiply the number of crates by the number of boxes in each crate. This can be expressed mathematically as: \[ T = C \times B \] where \( T \) is the total number of boxes of cereal. 3. **Substitute the known values into the equation:** \[ T = 9 \times 20 \] 4. **Perform the multiplication:** - Calculate \( 9 \times 20 \): \[ T = 180 \] 5. **Conclusion:** - The total number of boxes of cereal in the warehouse is \( 180 \). ### Explanation of Properties Used: - **Multiplication Property:** This property states that when you multiply two numbers, the result is the same regardless of the order of the numbers (commutative property). In this case, it doesn't matter if we think of it as \( 9 \times 20 \) or \( 20 \times 9 \); the result will be the same. - **Associative Property:** If we had more factors, we could group them in any way to simplify calculations. For example, if we had \( 9 \times (10 \times 2) \), we could first calculate \( 10 \times 2 = 20 \) and then multiply by \( 9 \). Thus, the warehouse has a total of \( 180 \) boxes of cereal.