If your business currency is the Swiss Franc – you can use a special feature – 5 Rappen rounding on the final invoice summary.
All you need to do is go to Settings -> Company Profile -> check ‘Round to 5 Rappen’:

Save your settings and check out what you will get on the invoice totals:

You will notice the result is rounded up to the nearest coins (to 0 or 5 or 10).
Note: the logic of rounding up to 5 Rappens is the following:
Multiply the value with 20, then round it to zero fractions (no numbers after the decimal separator) and divide it by 20.
Example:
1,000 – 1,024 → 1,024*20 = 20,48 rounding to 20; 20/20 = 1
1,025 – 1,074 → 1,025*20 = 20,5 rounding to 21; 21/20 = 1,05
1,075 – 1,099 → 1,089*20 = 20,78 rounding to 22; 22/20 = 1,10