We have 2 types of amounts:

1. DutyFree Amount.
2. TaxIncluded Amount.

Conversion Formula is :

DutyFreeAmount * 1.21 = TaxIncluded Amount

TaxIncluded Amount / 1.21 = DutyFreeAmount

Original Amount (TaxIncluded Amount): 38497.79

We calculate DutyFree Amount : (divide it by 1.21 & roundOff to 2 decimal points)

38497.79 / 1.21 = 31816.3554 ~ 31816.36

Now we recalculated it to the original TaxIncluded amount

31816.36 * 1.21 = 38497.7956 ~38497.80

Delta: 38497.80 – 38497.79 = .01

How do we solve this problem? We have a functionality where users can switch the amount on the listing page of devices from DutyFree Amount to TaxIncluded Amount and vice-versa.
Due to this, we have to perform calculations on user action simultaneously.