Section 4: Programming 269
 Press Comment 4000 STO 1 Initial downpayment STO 2 (\$4000). 1.005 STO 3 Monthly inflation factor (1.005). 2000 STO 4 Initial savings STO 5 (\$2000). 185 STO 6 Monthly savings (\$185). 1.01 STO 7 Monthly interest factor (1.01).
Note that the initial downpayment is stored.in both R1 and R2. This is because in our program r1 will remain the same as the initial value but R2 will contain the downpayment in successive months. We can at will reset R2 to the initial value saved in R1 and start over again. The same reasoning holds for R4 and R5 containing the initial savings.
One final word before we actually start our program. Normal procedure is to write the entire program sequence, enter it, and then test it. For the sake of greater understanding, we will write one label at a time and obtain the answers for that segment of the problem as we go along.

### Programming Label A : Monthly Total Downpayment

1. Switch to W/PRGM.
2. Press fPRGM to clear memory.
3. Key in the sequence of steps below.

 KEYENTRY CODESHOWN COMMENTS LBL 23 A 11 RCL 2 34 02 Dnpmt RCL 3 34 03 Inflation factor × 71 STO 2 33 02 New dnpmt RTN 24

 KEYENTRY CODESHOWN Dnpmt × 1.005 = New Dnpmt