I try to do the following calculation in both excel and with the texas ba II plus calculator but I get different answers for some reason.
10YR annual bond coupon 6,5%, mv=1089,25 fv=1000

I get a YTM of 0,05367955=5,36% BUT in excel I get 5,33%
This is a 0,03% difference but it happens for time to time for some reason and I can’t understand why?
Also, if I try to use the financial calculator functions, and plug all values straight into the buttons “FV, PMT, PV, N” and try to CPT the “I/Y” then I get 26.62906485 for some reason? I use 9decimals but I don’t understand what the problem is here. It would be cool to be able to use the financial calculator functions for the exam as well.

the formula you have used on the hand-written sheet gives the approximate yield, so it’s no surprise if there’s a small difference between that and the exact yield

The discrepancy in your YTM calculation could stem from differences in how Excel and your calculator handle bond pricing conventions or rounding. Double-check the input values and ensure you’re using the same formula for both calculations to eliminate any variations.

Thank you so much! You made my week, this was the issue. Now I get the EXACT same answer as in excel with nine digits 5,32581297 on my calculator. I really started to question myself haha