Calculate Total Cost: Multiplying $1.50 × 100 for Class Supplies

To solve this problem, we'll use straightforward multiplication:

• Step 1: Determine the cost per pack, which is $1.5$ dollars.
• Step 2: Determine the number of packs needed, which equals the number of students: $100$.
• Step 3: Multiply the cost per pack by the number of packs:

$\text{Total Cost} = 1.5 \times 100$

$\text{Total Cost} = 150$ dollars

Therefore, the total amount paid by the teacher is $150$ dollars.