Final answer:
Ervin shared 3/4 meter of plastic cover with his classmate, which is the difference between the initial 1 meter he had and the 1/4 meter left with him after sharing.
Step-by-step explanation:
Ervin bought 1 meter of plastic cover for his notebook and after sharing, he had only 1/4 meter left. To find the part of the plastic cover Ervin shared, subtract the amount left from the total amount initially bought.
Initially, Ervin had 1 meter of plastic cover.
After sharing, he has 1/4 meter of plastic cover left.
Amount of plastic cover shared = Initial amount - Amount left
Amount of plastic cover shared = 1 meter - 1/4 meter = 3/4 meter
Therefore, Ervin shared 3/4 meter of the plastic cover.