The first price reduction of a product is 10%, and the second price reduction is 10%. How much is the total price reduction in the two times fast

The first price reduction of a product is 10%, and the second price reduction is 10%. How much is the total price reduction in the two times fast

The present price is the original price
1×(1-10%)×(1-10%)=81%
The total price reduction is two times
1-81%=19%