I've been beating my head against the wall trying to figure this out. I'm usually smarter that this...

here's what I have, a simple column of numbers that I want to subtract each new input from the top number. It's a weight loss chart and I want to know how much I've lost in total, with additional data being put in daily.

For example:

A1:Starting weight: 250
A:2 Day one: 248


A:3 Day two: 245
A:4 Day Three: 244
A:5 Day Four: 240
A:6 etc. etc for day

A:50 =Current 'total' lost based on A:1 - last day in sequence


cumuluative total lost would subract each number in the sequence but only that number from 250. Meaning on day four it would take 250-240 to come up with 10 pounds but on day two it would subtract 245 from 250 to show a loss of 5 pounds. Of course I could wait until the end and just subtract the bottom number from the top, but I want to track it daily.. what am I missing?

I feel silly even asking this because the answer is likely so obvious an dI'm over thinking it. So thank you for any help