As a math tutor for 15 years, I have tutored hundreds of students from all the grade levels. I found most of the students were not comfortable with mathematics. More than 80% of them said, "the mathematics is very hard." Why do most of the students find mathematics a hard subject and try to avoid it? The answer for the above question is hidden in a simple example. I always give the example of stairs to my students, and giving the same example in this article. I compare the steps of a staircase to the concepts in mathematics. As this is very hard to reach higher floors of a building without stairs (or elevators these days), same way learn higher concepts in mathematics without learning basic concepts is very hard.
Each grade act as a step in the whole staircase to the mathematics high_rise building. Performing poor in math in any grade is like breaking some steps in the whole staircase. As broken steps make the whole staircase risky or scary to use in the future, incomplete math competencies in lower grades make math very hard in the high school. So, what it takes to be smart in mathematics? My answer is; stay focused on math in each and every level of your studies. Participate in your class math practice sessions. Ask your teacher lots of questions until you are not clear about any concept. Mathematics is a subject of solving the problems on paper by hand rather than only to read them. As in case of Social Studies taking more readings make you smart, in math practicing lots of problems and solving them by hand makes you smart. To practice mathematics, math workbooks are the good source. You learn a concept in a workbook, then in the same booklet there are more problems on the same concept for practice. Another good method to practice mathematical concepts is using math worksheets and you can print math worksheets free of charge from the web.