en_tn/num/05/07.md

the price of his guilt

Here the person's "sin" is referred to as his "guilt." AT: "what is considered a suitable amount of money for the wrong that he has done" (See: rc://en/ta/man/translate/figs-metonymy)

add to the price one-fifth more

This means the person must pay an extra one-fifth of the price that he owes.

one-fifth

This is one part out of five equal parts. (See: rc://en/ta/man/translate/translate-fraction)