The phrasal verb Add Up can be used to talk about a calculated a total sum: 'The waiter added up the bill and the total sum was $10'.
Add Up is also means to make sense: His theory doesn't add up. 'I don't think he did enough research'.
Add Up To is used to talk about an equaled amount. E.g. 'The total bill added up to $10'.
The phrasal verb Break down + noun can be used to talk about analysing something in detail: "You need to break down the maths problem in order to solve it properly."
Break down is also used to talk about something that has stopped working properly: "Can you please come and pick me up from work? My car has broken down."
