Let's go step by step to solve the questions.

1. What is the amount of the discount on the cell phone?

The base cost of the cell phone is $380, and the discount is 20%. The formula for calculating the discount is:

$\text{Discount Amount} = \text{Base Cost} \times \text{Discount Rate}$

$\text{Discount Amount} = 380 \times 0.20 = 76$

So, the discount amount is $76.

2. What is the total cost of the cell phone?

After applying the discount, the total cost is calculated by subtracting the discount amount from the base cost:

$\text{Total Cost} = \text{Base Cost} - \text{Discount Amount}$

$\text{Total Cost} = 380 - 76 = 304$

So, the total cost of the cell phone is $304.

3. Subtracting a 20% discount from the base cost of an item is the same as multiplying the base cost of the item by what decimal factor?

Instead of subtracting 20%, you can directly multiply the base cost by $1 - 0.20 = 0.80$, which represents the remaining 80% of the price.

4. Using multiplication instead of subtraction, calculate the total cost of the cell phone.

We can use the decimal factor (0.80) to calculate the total cost:

$\text{Total Cost} = \text{Base Cost} \times \text{Discount Factor}$

$\text{Total Cost} = 380 \times 0.80 = 304$

So, using multiplication, the total cost is still $304.

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Let me know if you'd like more details or have any questions!

Related questions:

1. What is the formula for calculating a percentage discount?
2. If the discount was 25%, how much would Carlos save?
3. What would the total cost be if Carlos got a 30% discount?
4. How does the decimal factor change for a 15% discount?
5. What would happen if Carlos applied an additional 5% discount after the first 20% discount?

Tip: Multiplying by a decimal factor is a faster way to calculate a discount because it combines subtraction and percentage in one step.