I am learning C#, ASP.NET and MVC. I am making an application and I am just wondering about the best way to go about it. It is an application that takes in water readings input by a user and some values are gotten automatically from the input each day, with some of the readings only being taken once a week. My first problem is what is the best way to make the table(s). There's values for every day and I'd like them split up into weeks too. Should I have one big table or many, maybe weekly? I feel weekly would be inefficient though.

Each week has to interact also, with values from the next week needed to calculate values for the current one. For example, say there's a row in the table called "Water Reading" and the columns are "Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday" and a total usage column at the end. So in week 1, that readings are taken each day, and when it get's to the Monday in week 2, the reading on Monday in week 1 is subtracted from the Monday in week 2 to get the total usage, and that is put in the total usage column in week 1.

A similar thing is done for each day, eg, Monday's reading is subtracted from Tuesday's reading to get Monday's usage.
I'm just looking for pointers and ideas on how to organise the tables and ways to have interactions mentioned above.