In any Math problem there is a paramount need to read the question carefully from beginning to. Understanding the question is not the hard part. The challenge is how to convert English statements to Math workings.
This answer is going to be lengthy.
If you develop a set of rules for solving math problems as early as possible you can then use the same set of rules at every stage of your learning process. This fast math trick for instant calculation will have you correctly answerin. If the problem is particularly complex you may need. 100 Quick and Easy maths shortcut tricks.