Is there any manual about how use calculation or formula

I am Jayden, I wonder where I can find manual about how to use calculation or formula to calculate field
I have 5 field need do calculation and show out the total
1.) Part Price
2.) Manhour
3.) Labor
4.) Total
5.) Total Amount

labor is example (50/100) x 23  where 50 is hour and 23 is dollar

Manhour is 50

Total is Part price + labor

Total Amount is Total Amount is Total up all data inside Total field ( if have 100 data inside the table it will total up all)
I search ready post manual I cannot found any manual show the calculation
please help