There is no math in IELTS and TOEFL. Especially IELTS, there is no need to calculate anything in it. Foreigners' concept of numbers is not very good. If there are numbers in the exam questions, they usually write directly or hear several different ones. Write down the correct answer. You absolutely don't need to calculate. It's the SAT for math. This foreign college entrance examination not only tests mathematics, but also physics and chemistry.