How is 8% sales tax like an 8% increase

Because when you buy something and there is a sales tax it adds the choosen percentage to the price. So like if there is a Bike for $75 and the Goverment wants 8% of the $75 the store would charge $6 more because 8% of $75 is $6 and the sales tax would be that $6

A sales tax is an extra amount that is added onto a total. A percent increase is almost the same cause 8% sales tax and 8% increase is both the same amount of the total that is going to be added onto the total.