宿題が思っていたより簡単だったって英語でなんて言うの？

The phrase "piece of cake" means that something is very easy. I hope that this helps :)

The word 'set' is a more precise way of saying that the teacher gave you homework. Usually when something has been set, like a piece of homework, it implies that it is something we have to do and it has a deadline.

Sometimes we might feel that our homework will be challenging and we have so much we need to do. However, sometimes it can be a very simple project and we don't have much problem with the homework. If we want to explain this, we can use some expressions such as: 1) The homework was a lot easier than I thought it would be! 2) That homework was super simple! 3) That homework was easier than I expected!

If something is a 'doddle' then it is very easy. Similarly, if something is said to be a walk in the park, it is a simple task or operation or process. "Applying for a UK visa is a doddle."

This is a way of saying that you thought the homework was going to be difficult but you were surprised to find out that the homework was actually easy.

If homework was easier than you thought it was going to be, you can say "it was easier than I expected." 'Expectation' is the thought or feeling about that something is going to happen, and how it is going to be. You can use it as a comparison. If the homework was more difficult than you thought it was going to be, you can also use 'expected' for that: " The homework was harder than I expected." "Easy peasy!" is a fun way of saying in English that something is/was extremely easy.

If something is easy then it is also said to be 'not difficult' or 'wasn't as difficult' if you think about something being a cerain way as well as saying the way you 'thought you can also say 'imagined'

"It was easier than I thought" This expression refers to a task being easier than what was first thought or told. "piece of cake" Is a expression used when something for example a task, is very easy to do/complete.