HP 12 C simple interest calcuation

[sam]

Hi all,

I am new to this forum. Recently, I am excited by the HP 15C limited edition and trying to recall the memory of using my Singapore version of HP 12C as well.

Back to the subject, I want to calculate the principal which will accumulate to $10,000 at simple rate 7% p.a. over two years.

FV = 10,000
i = 7
n =2

The PV is calculated as -8,734.39.

As you may know, this is not correct given the formula PV*(1+2*0.07)=10,000. The correct PV should be 8,771.93

I figure out that it is the default compound interest calculation in HP 12C.

My question is that is there a way to make HP 12C use simple interest method to work out the PV? I understand there is a key STO EEX for old period calculation but it seems that is not useful here.

I would appreciate your assistance. Many thanks.

Sam

[peacecalc]

Hello Sam,

the formula used by HP 12C accumulates the interest:

PV*(1+0.07)^2 = 10,000

So you get PV = 10,000/1.07^2 = 8734,39. That is exactly what the calc you told.

The situation you calculate is different.

greetings peacecalc

[sam]

Hi peacecalc,

Thanks so much for your assistance. I did not expect to get it so quick.

I understand what you said is right that I told the HP 12C to calculate like this.

However, this is because i do not know how to tell the calculator to work the PV out in a simple interest calculation.

The denominator 1.07^2 is the compound interest method, i.e., (1+0.07)*(1+0.07).

But I like to calculate this in the simple interest method which should be:

PV*(1+0.07*2)=10,000

Perhaps I should not use the financial register to work this out. A simple formula below is ok

10,000 enter
0.07 enter
2
x
1
+
/

Best regards,
sam

[fhub]

Quote:

---

Perhaps I should not use the financial register to work this out.

---

Well, although TVM calculators are usually not used for 'simple' compoundings (that's just _too_ simple ;-)), you _can_ do it if you really want:

You only need to always set n=1 and enter n*i for i, that's all.

Franz

[Thomas Ritschel]

Hi Sam,

one can still use the financial registers for a simple interest calculation.
You just need to use a "total interest rate" by multiplying the yearly interest rate by the number of years and then use n = 1:

10,000 FV

0.07 ENTER

2 x i

1 n

PV

This should give you PV = -8,771.93 as requested.

Kind regards,
Thomas

[sam]

Thanks for all. The method n=1 and treatment of i is useful although it is a bit odd.

Sam

[fhub]

Quote:

---

The method n=1 and treatment of i is useful although it is a bit odd.

---

No, it's not odd at all. Odd is using a TVM calculator for a problem with a simple (i.e. not compounded) interest rate. ;-)

Franz