English is an universal accepted language.
Now,If english wouldn't have been there in the world, the world wouldn't actually be a global village as it is now. Maths is not the subject that helps one to survive, but it is english. Yes, it is a point that every country is actually not a english speaking but even if many countries are, the countries that don't speak english will never develop if it doesn't have english as a medium and that's because english is the only universaly accepted language. In the field of science, why do you think there are scientific names of things?(a) And in which language are those names of? Some info, All the scientific names and terms are in english. All countries do not speak english, sure but the scientist and the managers of the country do. So, English is must. Maybe the country is actually not a englsih speaking one but if there is absolutely nobody knowing that language, development in that country is impossible. Think about it, which scientist doesn't know english and has come into international fame? Maths doesn't help one to survive but english in the english speaking countries do and also in the non-english speaking countries as it sustains development. Suppose a country has no one speaking english, so, no one can communicate with the top countries in this world(very practically). No support, No inventions, no economy, low healthcare,education is limited but yeah those people are excellent mathematicians...is that of any use? obviously not.In fact, that country will fail to develop and human's life there will be tough.