How to solve for future value - Casio FX-260 Calculator

Actually, you don't need the y^x key.

Clear the financial registers with 2nd [CLR TVM]
Enter the present value: 1 0 0 0 0 0 0 +/- FV
Enter the future value: 2 0 0 0 0 0 0 FV
Enter the interest rate: 7 I/Y
Compute the number of periods: CPT N

If necessary, press f [FIN] to clear the financial registers.
4 0 0 0 0 PV ( enter present value )
3 . 3 i ( enter interest rate )
4 0 N ( enter number of periods)
FV ( compute future value )

2nd [CLR TVM] (clear TVM registers)

2 4 0 0 +/- PV ($2400 initial investment, negative because you're paying it out)

6 I/Y (6% annual interest)

1 N (one year)

CPT FV (compute future value, see 2544.00, the value after one year)

5 N (five years)

CPT FV (see 3211.74, the value after five years)

1 0 N (ten years)

CPT FV (see 4298.03, the value after ten years)

2nd [CLR TVM] (clear old data)
6 2 5 PV (present value)
8 I/Y (annual interest)
1 2 8 4 +/- FV (future value)
CPT N / 1 2 = (compute number of months, divide by 12 to get number of years)

2 0 0 0 0 +/- PV (present value, negative because you're paying it out)
5 *P/YR (5 years)
1 0 . 5 I/YR (interest rate)
FV (calculate future value, about 33,732)

That depends on the interest rate.

2nd [CLR TVM] (clear previous data)
5 0 0 0 PMT (monthly payment)
2 0 2nd [*P/Y] N (20 years of monthly payments)
annual interest rate I/Y (annual interest rate)
CPT PV (compute present value)

At 10% it's about $518,000

The example found on Texas Instruments Knowledge Base will demonstrate how to calculate future value on a TI-83 Plus.

The Knowledge Base can be accessed by clicking on the URL below:

http://epsstore.ti.com/OA_HTML/csksxvm.jsp?nSetId=68565&nUsePub=NO&jttst0=6_23871,23871,-1,0,&jtfm0=&etfm1=&jfn=ZG9FB38B4A2AA5FD2B95856A86C456B04891A1DF1818254BD8745136644414BBD77A84F7D2D719EC988ABF354C41ACA7922D