When selling courses on TeachingHub, you have the option to include tax in your selling prices. You can specify the tax rate under the 'System settings' as a percentage. If you choose to apply tax to the course price, your students will need to purchase the course at the price inclusive of tax.

Figure 1. TeachingHub Adding Course Selling Tax

Figure 2. TeachingHub Course Checkout Page

Your course price is $55 and you have added 2% as tax. 

$55x2%= $1.1 [Your course tax is $1.1. Your student has to provide this amount extra as tax with course price]

So the course price is:

$55+$1.1=$56.1

So, the student has to pay $56.1 for purchasing a course.

NB: To disable this tax amount, you can provide the 0% tax in the "System settings" option.