Casio dr 250 hd calculator keeps resetting back to 5% tax code after several weeks being on 6%. This doesn't make any sense. Why would it? I turn it off at the end of the day.

That is the correct program it seems your program is corrupt, just wipe out everything and start afresh

HOLA COMO ESTAS NECESITO SABER CUANTO CUESTA LA CALCULADORA SUMADORA DR-250 HD

Press AC twice Hold down % set key for 4 seconds. Input tax rate (6%). Press Tax+ key, then press % set key
Source: http://www.casionz.co.nz/Site/CASIO/files//settingandusingtaxandexchangekeys.pdf

Observe the devices function keys to ascertain any menu or mulltifunction buttons. Multifunction keys perform several features. First the multi key integrates several features to minimise the extraneous requirements wit micro computer keypads. Second, multifucntion keys perform the additional fucntions least visible at initial observation. Calculors as simple computers onlyl produce transaction requests though allowing to adjust features to suit productivity. Perform an observe of the device to familiarise with the adjustment status condition. In the instance were the device were dessign least to allow an alteration of calcultion percentages makes alteration unachievable. Refer to the devices oner user guide to ascertain the capacities if functionalities among several resources made available from the manufacturer.

Hi,
Try the link below.

http://www.casio.com/support/techsupport/calculators

To change tax rate on Casio DR-210TM:
Hit <CA>
Hold <%> for 5 sec until '0' re-appear
Enter 'Tax Rate' and <TAX+>

So just 5 easy steps to change the rate

1 press the AC button
2 hold down the SET /SET % / button for a few seconds
3 press the TAX + button
4 input the rate /in your case 6/
5 press SET button again
And you are done. You can also check it - press the Tax + button and the current tax rate will appear

Hope I helped !

refer to dr-250hd calculator

make sure you are in "print mode" step 1 pess the AC button step 2 press and hold for two seconds the % button step 3 press the tax+ button step 4 input tax rate step 5 press the % button now check to make sure that is correct.

Printing models (except HR-8TE): 1. Have calculator in ?print? mode 2. Press [CA] 3. Hold [SET/%] key for about 3 seconds 4. Input the tax rate 5. Press [TAX+] 6. Press [SET/%]