what formula do i need to calculate 75% of a number which then decreases by 90% | andie856603 | 5/20/11 10:15 AM | Before you post! Please search for your answer first. If you haven’t searched for an answer, then click on “edit question” above to return to our suggestions on how to find your answers. Providing the following information will help us troubleshoot your issue:Browser & Operating System (e.g. Firefox/Mac OSX): Free consumer account (@gmail, @yahoo...) or Google Apps account (@yourdomain): Describe the steps you took that produced this error: Copy and paste any error messages: |

Re: what formula do i need to calculate 75% of a number which then decreases by 90% | Bipan Kundal | 5/20/11 7:57 PM | =((A1)*75%)-((90%)*A1*75%) where A1 is the original number |

Re: what formula do i need to calculate 75% of a number which then decreases by 90% | Ted J | 5/20/11 9:56 PM | The formula works however I would recommend andie856603, will your two respective percentages always be 75% and 90%? If they change we can write you a formula that allows you type change those values and always have the correct result. As a note, I chose the decimal forms because writing a number as a percentage is a formatting step and I generally encourage keeping numbers in calculations in the purest forms...(so one could argue for =(A1*(3/4))-((9/10)*A1*(3/4)) as well but I thought it was uglier)... Just my opinion though... |

Re: what formula do i need to calculate 75% of a number which then decreases by 90% | andie856603 | 5/21/11 2:35 AM | thank you both for you help with this is much appreciated what i also need to do with this also is add another value...yes the original number will stay the same but where would i enter the column/row to show if it was the 1st/2nd/3rd etc calcution of this number ie 1 would be 75% of original then 2 90% of that 3 90% of 2..... 4 90% of 3 and so on |

Re: what formula do i need to calculate 75% of a number which then decreases by 90% | Ted J | 5/21/11 8:29 AM | Try this: Let A2 be where you type the original number. Type "Original Number" in A1 as your header Let B2 be Calculation 1 and the formula =A2*.75. Type "Calculation 1" in B1 as your header Let C2 be Calculation 2 and the formula =B2*.9. Type "Calculation 2" in C1 as your header Let D2 be Calculation 3 and the formula =C2*.9...and so on You can copy the formula from C2 across as many times as you want by using Ctrl+C and Ctrl+V. The copied formula will always use the cell immediately to the left and multiple it by .9. |

Re: what formula do i need to calculate 75% of a number which then decreases by 90% | andie856603 | 5/21/11 11:25 AM | o.k again thanks for helping me with this your answer it great although would it be possible in add this into the original formula rather than have extra colums so i could change the number to 1,2or 3 etc to then show 1st,2nd or 3rd calculation etc in one column? |

Re: what formula do i need to calculate 75% of a number which then decreases by 90% | AD:AM | 5/21/11 6:53 PM | Try: B2: calculation step (0, 1, 2, 3 etc) C2: =IF( LEN( A2 ) ; A2 * ( 0.75 ^ SIGN( B2 ) ) * ( 0.9 ^ MAX( 0 ; B2 - 1 ) ) ; IFERROR( 1/0 ) ) HTH Adam |

Re: what formula do i need to calculate 75% of a number which then decreases by 90% | Yogi Anand | 5/21/11 8:37 PM | Hi Andrea: I believe you and I have worked on this problem or a very similar one before. In any event, I have used the following formula ... =ArrayFormula(if(C:C,StartingNumber*x%*y%^(row(C:C)-1),iferror(1/0))) as shown in the illustration for you in my Blog on Cloud Computing -- Google Docs Way yogi_calculate X Percent Of A Number Which Then Is Successively Decreased By Y Percent Please check it out to see how this works for you. Cheers! Yogi |

Re: what formula do i need to calculate 75% of a number which then decreases by 90% | andie856603 | 5/22/11 7:22 AM | hi yogi yes you have helped me before & your formula works perfect for me as i am expanding my game i am adding additional data to my spread sheet this calculation is very complex perhaps you would like me to share the sheet with you then i can explain more |

Re: what formula do i need to calculate 75% of a number which then decreases by 90% | andie856603 | 5/23/11 12:24 PM | thank you problem solved :o) |