As a teacher I have seen so many people pay for tutoring, buy practice books, etc. Usually, you can get all the help your child needs for free. Teachers often get kits with their textbooks of all the things they need to supply each student. These kits have to be used for several years, so the teacher cannot give you the supplies. However, if you are a parent that can be trusted, the teacher will often let you borrow things. You could probably get things like rulers, sets of coins and bills for money practice, protractors, compasses, calculators, small clocks for practicing time, counters, shapes, fraction bars (to help with learning fractions,) etc.
Another thing that teachers get with their textbooks is extra practice books. If your child needs help, have them do some extra practice at home. Teachers cringe on the inside when you ask for extra worksheets, because they honestly don't have the time to make more copies. If you would like the extra help for your child, ask the teacher to write down the lesson numbers she has planned for the next week. Then go into school (schedule a time with her ahead) and make copies from the extra workbooks that the students don't use in class. Usually a teacher will work with you on that and be happy to give you the books if you will look up the pages and make the copies yourself. Most books have the lesson numbers on each page somewhere so you should be able to figure out what to copy from the list of lesson numbers that you asked for.
One final thing that parents often asked me about is tutoring. Honestly, tutors can be counterproductive sometimes. If the tutor doesn't teach a skill the same way that the teacher did, it can be confusing to the child. Also, the tutor doesn't know how the test will look. So, who knows all of this information besides the teacher? The textbook companies do. In most cases they are the ones that write your child's tests, so they would know how to tutor your child. They also are very likely to present the material in the same way that the teacher did, since she is teaching from their books. How are you going to get the textbook company to tutor your child? Actually, most companies provide free e-books online. This is great because your child can do homework on the computer using the e-book and not have to lug home 20 pounds of book weight. Most of the time, these sites will also provide extra practice, re-teach lessons, games, and tutoring for each lesson in the book. You will probably have to ask the teacher to give your child a user name and password to access the site. Once you have that information, you should have access to all kinds of resources (for free) that hit on the exact skills your child is covering in class.