After teaching math for over 30 years, I have taught a range of students, including some who found it "challenging." Even the least able were able to understand some simple arithmetic — if you charged someone $10 and they charged you $10, then nobody was better off and you were probably both annoyed. This works the same for larger numbers.
Why can't our world leaders understand this? A tariff war with matching increases will not help anyone in the long term. Get back to looking for positive approaches.