Maths is not just about calculations. Maths is used in our daily life. For example, while playing basket ball we use the concept of parabola, while defining the speed of the car, we measure the distance. Most basic example is counting and distributing chocolates amongst your friends, it involves the concept of division.
Therefore, maths is everywhere, one just needs an insight on how to utilise it. One major step to improve in any subject, especially maths, one needs to have the willingess and interest to do it. Rather than making it a boring task, the way you practice maths should be fun.
I highly recommend using games such as kahoot or any other site, which helps you to pratice maths and any other subject in the form of fun timed quizzes. It will challenge your capabilities and help you ace the subject.
Another important step towards improvement is consistent practice. Giving some time everyday will help one to get more and more confident because "Practice makes man perfect." Everybody is fond of playing video games, so even that requires maths. Quick reflexes, problem solving, quick understanding and the games related calculations, for troops and aiming the target, are the skills you gain if you learn the skill of quick calculations and understanding.
The improvement is step by step and not overnight, so any individual should work at their own pace and try not to hurry. Each time beat your own score becuase thats what meant by the word improvement. You are supposed to know the multiplication tables at least till 15, so that you can make basic calculations, quickly as possible.
The more you think of a subject as fun and challenging, the subject wont just remain academics, but a vital part of your life. Do not burden yourself at the last days of your exam instead consistenly pratice it, because it is the ultimate way towards success.