Question

Cameras R Us has a sale for 25% off camera bags, which is a discount of $20. Explain how you can set up a diagram to find the original cost of the camera bag. Indicate the number of columns necessary to fit the situation.

Answer 1

To find the original cost of the camera bag at Cameras R Us using a diagram, you can set up a column-based visual representation that helps illustrate the relationship between the original price, the discount percentage, and the final sale price.

### Step-by-Step Diagram Setup:

1. **Define the Columns**:
You will need **three columns** to effectively illustrate the situation:
- **Column 1**: Original Cost (OC)
- **Column 2**: Discount Percentage (DP)
- **Column 3**: Amount Discounted (AD)

2. **Fill in Known Values**:
- In **Column 2** (Discount Percentage), you write **25%**. This represents the percentage of the original cost that will be given as a discount.
- In **Column 3** (Amount Discounted), you write **$20**. This is the amount that the camera bag is discounted.

3. **Calculate the Original Cost**:
To find the original cost (OC), you can use the formula:
\[
AD = OC \times DP
\]

Rearranging this gives:
\[
OC = \frac{AD}{DP}
\]
Substituting the known values into the formula, we first need to convert the percentage into a decimal:
- 25% = 0.25

Now substitute the values:
\[
OC = \frac{20}{0.25}
\]

4. **Perform the Calculation**:
To perform the calculation:
\[
OC = 20 \div 0.25 = 80
\]

### Conclusion:
After filling in the diagram with the relevant columns and performing the calculation, you conclude that the original cost of the camera bag is **$80**.

### Summary:
- **Number of Columns**: 3 (Original Cost, Discount Percentage, Amount Discounted).
- **Calculation Method**: Use the relationship between discount percentage and amount discounted to solve for the original cost.