The negative sign is basically used to indicate cash inflow and outflow. Don’t worry too much about it in FV except when calculating the rate. If I remember correctly the sign matters then. I think the reason is you are entering a negative in your calculator already. This is why the answer is coming out as a positive. I think what Schweser is trying to say is to spread out an outflow over 5 years which is why they are showing the negative sign in the answer. Did you check the errata sheet by any chance?
@ensenmason The calculator calculates it as an investment, i.e. you’re telling it you’ve PAID IN $1000 at the start, so at the end you should be PAID OUT $1,610. So the signs are opposite to each other (i.e. you enter in -1000, FV comes out as +1610).
Since you’re simply calculating the future value of a payment, the signs are the same.
So I’d use conceptual knowledge to double-check on what the signs should be. Just treat it as cashflow as @CFAcharterwannabe and you’ll be alright 🙂