On a trial run, a new cafe sold 20 sandwiches in 10 minutes. Tomorrow, the business will be open for 3 hours. To help determine how many sandwiches to make, the cafe manager performs the following calculations:

Step 1: 20 sandwiches × 10 minutes = 200 sandwiches per hour

Step 2: 200 sandwiches per hour × 3 hours = 600 sandwiches

What error did the manager make?

The manager should have divided 20 by 10 to calculate the number of sandwiches sold per hour.
The manager should have added 20 and 10 to calculate the number of sandwiches sold per hour.
The manager should have multiplied 20 times 6 to calculate the number of sandwiches sold per hour.
The manager should have divided 200 by 3 to calculate the number of sandwiches.
The manager should have added 200 and 3 to calculate the number of sandwiches.