"a piece of cake this means very easy the exam was a piece of cake under the weather you're not great or you're feeling slightly ill i'm feeling under the weather today cost an arm and a leg something is very expensive the hotel cost an arm and a leg in the long run so this means over a long period of time for example it's difficult now but it will help you in the long run on the same page to have the same understanding as someone else let's make sure we're on the same page"