I agree with kaywinnet Frye, but there are also free websites. I recommend khan academy. Also, if you are willing to spend money, subscribe to lumosity. Practise every day with both of these sites.
How can I get good at Math? I'm having trouble with division and multiplication.
1) Make a chart of the multiplication tables. Then memorize it. That will help you with division too.
2) Tell your teacher. Ask her to seat you in the front. That will help you to pay attention. Ask her for extra help too.