# Thread: Can type this in my calculator correctly!

1. ## Can type this in my calculator correctly!

Hi all,

I cant seem to get the correct answer to this equation (attached image):

The answer is -0.06 as shown in the question, but when I complete it in my calculator I get a different answer

Staring at this question for hours now.

(What I do: I first complete the the 2nd bracket and then multiply that by 108/365 which gives me 0.02739. I then hit the Ln button on my calculator and do 2510/2600 and add that answer to my 0.02739. Next I type 0.2306 SQUAREROOT(108/365) which gives me -0.01847)

Any pointers would be really apprecaited.

Thanks everyone.

2. Sorry, the thread title is meant to be "Cant type this in my calculator correctly!".

3. Originally Posted by bamboozled
Hi all,

I cant seem to get the correct answer to this equation (attached image):

The answer is -0.06 as shown in the question, but when I complete it in my calculator I get a different answer

Staring at this question for hours now.

(What I do: I first complete the the 2nd bracket and then multiply that by 108/365 which gives me 0.02739. I then hit the Ln button on my calculator and do 2510/2600 and add that answer to my 0.02739. Next I type 0.2306 SQUAREROOT(108/365) which gives me -0.01847)

Any pointers would be really apprecaited.

Thanks everyone.
Dear bamboozled,

Obviously, $\displaystyle 0.2306\sqrt{\frac{108}{365}}$ cannot be a negative value. I suppose the way you imput your expression must be wrong, if not the calculator is not working properly. Anyway the correct answer is -0.062443726......

4. Originally Posted by Sudharaka
Dear bamboozled,

Obviously, $\displaystyle 0.2306\sqrt{\frac{108}{365}}$ cannot be a negative value. I suppose the way you imput your expression must be wrong, if not the calculator is not working properly. Anyway the correct answer is -0.062443726......

Thank you Sudharaka,

I dont think the problem is the calculator but rather me entering in the expression incorrectly.

I have tried it again and again and still keep getting it wrong (I am not much of a mathematicial you see), would you by any chance be able to give me a little more of a break down on how to enter the expressions correctly in my calculator?

I dont see where I am going wrong, maybe I am using the Ln feature incorrectly (again, I am not much of a mathematician im afraid)

Thank you again.

Without knowing what model of calculator you have (or how it treats logs) we cannot answer comprehensively.

Below is my best guess

1. Open Bracket
2. Open bracket
3. type 2510/2600 into your calculator
4. Close Bracket
5. Press ln key
6. Plus
7. 108/365
8. Multiply
9. Open Bracket
10. 0.066
11. +
12. Open Bracket
13. 0.2306
14. squared key
15. Divided by 2
16. Close Bracket
17. Close Bracket
18. Close Bracket this should be the end of numerator
19. Divided by
20. Open Bracket
21. 0.2306
22. Multiplied by
23. square root button
24. Open Bracket
25. 108/365
26. Close Bracket
27. Close Bracket
28. Equals

6. $\displaystyle \dfrac{\ln \left(\frac{2510}{2600} \right) + \left(6.6\% + \frac{23.03\%^2}{2}\right)\frac{108}{365}}{23.06\% \sqrt{\frac{108}{365}}} = -0.06$

Since you have a big fraction, I would advise entering this:

$\displaystyle (\ln(2510 \div 2600) + (6.6\% + (23.03\%^2 \div 2) ) \times (108 \div 365)) \div( 23.06\% \times \sqrt (108 \div 365))$