That paper is really difficult. Your score of 70 is good, which suits you better. As long as you focus on the basics and make a set of medium-sized papers, your math will not be low. Don't worry, the set of questions given to us by our school teacher is really off-topic, which is not suitable for candidates in the national examination paper.
What's more, the difficulty coefficient does not include all the papers. It stands to reason that the difficulty coefficient of Grade Two is 0.6, but the set of questions is at least 3 or 4 times simpler.