Welcome to English in a Minute.
Do you find American idioms hard to understand? It's our goal to make learning them "a piece of cake."
Everyone in America knows this idiom because it's so easy.
A: Hey! How did you do on the exam?
B: I got an A. The exam was a piece of cake.
In American English, when you say something is a "piece of cake," it means it is very easy to do.
in the 19th and early 20th centuries, African Americans started "cake walks." They walked or danced around a cake in pairs, and the best couple won the cake. This is how the idioms "cake walk" and "piece of cake" came about -- both meaning that something is very easy to do.
And that's English in a Minute.