I envy your math skills, and your skill with a calculator, pen/pencil, notepad. I envy that you have the time to do all this. I can't imagine why somebody would want to do this, when the spreadsheet is so much quicker and more accurate (just a guess), but whatever.
One of the things that I like about my spreadsheet is the ability to do "what if's". What if I put two pounds more on the left front? Put the cursor in the left front cell, add two (or whatever) hit return, and there's your answer. Total kart weight, all three percentages (front, left, cross) front to back and LF to RR cross plus percentages and weight on the front cross and the rear cross. Don't know if the FC or RC will do you any good, but they're there.
Or; put in Front Left and Cross Percentages that you desire, and it tells you what each wheel needs to weigh to make those percentages.
Or; put in the individual wheel weights and it tells you what percentages you have.
Best of all, no errors. Ever.
Send requests for a free, fully operational, copy to
anunley@austin.rr.com It will not work in a handheld phone or whatever, you need a computer. Desktop, laptop, either one.
There's 29 spreadsheets in what I call Nine Sheets. Lots of karting related stuff. To be fully compatible you need Excel 10, but the generic spreadsheets work pretty well, all except the macros. You have to rewrite the macros for generic spreadsheets.