I always have roommates. And the most difficult math moment that would happen in my life is the time we go grocery shopping together. I love my roommates so we share grocery a lot, but I could not afford the whole bill so I always do math and note on the receipt, like this:

     Therefore I was inspired to create a 'Roomies Calculator' in order to make everyone's life convenient and efficient. The interface would look like this:

     I borrowed my Friends as the example in my interface wireframe. So, Ross Geller is the bill owner and he uploaded this photo of the receipt into the system. And Joey as a good friend he wants to see how much he should pay Ross.

     First of all, Joey called out this transaction, which was already transformed from photo into readable text, then he claims the beans, cauliflower, and Hawaiian red sea salt that he bought.

     Next, the right part of this application would calculate the amount and if there is tax or tip of this transaction for Joey to pay Ross. Finally, Joey taps Confirm to take further actions: send the money to Ross, or save the amount in the system.