piece of cake

这个数学题对我来说是小菜一碟。

This math problem is a ___piece ___of ___cake for me.

别担心，组装这个书架很简单。

Don't worry, putting this bookshelf together is a ___piece ___of ___cake.

我吃了两块蛋糕。

I ate two ___pieces ___of ___cake.

你想来一块蛋糕吗？

Would you like a ___piece ___of ___cake?