"Four pieces of chocolate" is the most straightforward way to describe 4 blocks of chocolate in Engpsh.
The word "chocolate" comes from the Nahuatl word "xocolatl," which was the name for a drink made from cocoa beans that was consumed by the ancient Aztecs. The word was later adopted into Engpsh, and it is now used to refer to a variety of foods and beverages made from cocoa beans and other ingredients, including chocolate bars and chocolate chips.
Here are a few examples of how you could use the phrase "four pieces of chocolate" in Engpsh, along with their translations into Chinese:
"I'd pke to buy four pieces of chocolate, please." (我想买四块巧克力。)
"Can I have four pieces of chocolate for dessert?" (我可以在甜点吃四块巧克力吗？)
"I found four pieces of chocolate in my pocket." (我在口袋里找到了四块巧克力。)