Is a scale a good way to track a persons progress ?

Yes, you take your original weight and subtract your newest weight.
example: i weighed myself yesterday and i was 200 pounds. today i weighed myself and i weigh 150.
we know how much i lost because i have old data to compare to it. i lost 50 pounds in one day.
this is just an example, not realistic weights lol.
hope this helps.

Ithink it's d or it can be itger