The difference between the amounts on your teacher statement and what you receive in your PayPal account is the PayPal transfer fee.
The receiver of the funds will pay Pay Pal Fees. The fees are subject to change as per Pay Pal. The Pay Pal Fees vary according to the amount transferred and the publisher's country.
PayPal fees have been revised. From August 21, 2020 payments onwards the Pay Pal fees are as follows
2% of the transaction amount up to $1.00
Russia / Ukraine
4.4% of transaction amount + 30c
Rest of World
2% of transaction amount up to a maximum of $20.00 USD