Answer:
3.5 meters
First, let us convert 300 millimeters to meters. To do this, we need to divide the length value by 1000:
Now, it is said that Dean uses 300 millimeters of yarn each day, which means that he uses 0.3 meters of yarn each day.
For 5 days, Dean used:
We will then subtract the length Dean used from the 5-meter yarn that he started with:
Therefore, Dean has 3.5 meters of yarn left.