بِسْمِ اللهِ الرَّحْمٰنِ الرَّحِيْمِ
The prophet (ﷺ) said: “Whoever fasts the month of Ramadan and then follows it with six days of fasting in the month of Shawwal, it will be as if he had fasted the year through” [Muslim]
Every deed is multiplied by 10. The month of Ramadan is 10 months worth of fasting, 6 days of Shawwal is 60 days of fasting which completes the year.
Remember, we have until the end of the month of Shawwal to finish these 6 days; they do not have to be done in a row.
May Allah make it easy to fast these short extra days.
Allah knows best.