Your aim should be to make math fun for your child and help them gain a solid understanding of the basics. Encourage your child to incorporate math into their daily activities, help them do mathematics worksheets, and then use the lessons therein to create fun activities for your child. The secret to learning math is to have an open mind about it. Just because you hated math doesn't mean your child should, and you will be doing them a disservice if you pass your negative feelings on to them. Make learning math fun, get a comprehensive set of mathematics worksheets to make it exciting and stimulating, and encourage your child's efforts all the way. Every math genius had to start with 1 + 1, just like your child.
But another person used the stairs to reach the same floor. This person found it very easy and reach there with little effort. Compare this person to a student who knows all the basic concepts learned in elementary grades. To learn grade six or grade seven math for this student will be easy. But there is another student in grade six and doesn't know the lower grade math concepts such as, times tables, factors or number system. This student is in the same situation as the person, who is jumping to reach third floor from the ground level. From the example it is very clear that mathematics in each grade have the same importance. So, you need to be focused on math in all the grades on all the basic concepts. Ask your teachers lots of questions. Keep asking until you are not clear about the concepts or topics you are working on.