Question 220863
Sometime a negative number seems like a ghost
and sometimes it's clearly visible.
It depends on what you're using them for.
(A)
Let's say I'm on a railroad track that runs east and west.
If I want to, I can say that if I go west, that's positive
motion, and if I go east, that's negative motion.
OK, I go W 1 mile, I go E 2 miles, then I go W 6 miles.
How far am I from where I started?
I went W +1 miles
I went E -2 miles
I went W +6 miles
1 - 2 + 6 = +5 miles
I am 5 miles west of where I started.
(B)
Let's say I owe you $5. I've got the $5, so
it's a (+) on my records until it's spent.
You're missing the $5, so it's a (-) on your 
records until I pay it back.
What does -$5 look like? Nobody's ever seen one,
but recordkeeping can't work without it.
Think of it as an empty pocket that only holds
a single $5 bill, and you're always reminded
that it's empty and needs to be filled.
It's the -$5 pocket.
Does that help at all? You need to keep
thinking about it.