Take stock of any stress you may have regarding testing...and try to make sure that doesn't get unduly transferred to your child. You want your child focused and positive as they take the test - not distracted by stress.
Buy practice test books. There are many types on the market and they can be purchased or ordered from most bookstores. These books will indicate on their front covers which tests they will help the child prepare for. Many buy two...of different titles. The variety is good and you can use one book to practice familiarization with testing and then use the other to create mock testing situations of a timed test.
Validate the answers. The answer sheets have been known to have typos. Don't just blindly compare your child's answers with the answer sheet and score solely on the comparison.
Have the child go over the practice areas. Check each answer and review them (right or wrong!) with your child. Help the child understand why he got a question right, why he got it wrong, or what he needs to do to get it right the next time.
Look for patterns of error, or weak spots in your child's test. Concentrate on these areas in both their school and in the test prep book. Remember – a weakness in reading might affect many areas of the test (including math!). Be sure to evaluate WHY the child is having difficulty in a given area.
Be sure that your child is familiar with general math terms (like "sum", "addend", "divisor", "quotient"), different types of instructions, etc. Go over terms in the instruction/question area of the practice book to be sure your child is familiar with them.
Have the child practice taking the tests under timed conditions. Time limits add stress to the situation and it helps if the child has practiced under these conditions.
Become familiar with a bubble answer sheet. Note that your child will only have to fill in bubbles for answers to questions. Name, address, and other data on the answer sheet will be pre-completed by the testers. For familiarity, we have provided example bubble answer sheets in the subsequent links. We are not presenting these as the actual bubble answer sheets. Note: we've tried to make the file sizes as small as possible, but they still could be a bit large for some slower Internet connections. Here is a smaller-sized file for viewing on screen to see what a bubble test sheet looks like and here is a larger file that will be more clear in printing - click to download this printable version (995k, PDF). And here is a web site where you can download bubble answer sheets for practice. You can also make your own bubble answer sheets.
Be sure to teach your child how to fill in the circles on the answer sheet. Remind them that only ONE circle can be filled in for each number. Also, it is very easy to skip a line on the answer sheet (especially if they skip a question they don't know). Show the child how to use a piece of paper, a ruler, or a pencil to mark their place on the answer sheet. Remind them to keep checking the number of the question with the number on the answer sheet.
If the child becomes stuck on a question, encourage them to skip it. Your child can always return to the question if there is time. Remind them that if they skip a question, they also need to skip that line on the answer sheet.
On the Iowa test, an unanswered question counts the same as an incorrect answer. So an effort should be made to complete every answer line and not leave any line blank - you might get lucky with the correct answer.
Let your child know that this is not a pass/fail type of test. These tests evaluate a broad range of skills. There may well be questions or problems that your child is not familiar with. Encourage them to guess if they don't know the answer and to move on to the next question.
Let your child know that other children may finish the test before she does. This can be unsettling for some children. Just because a child finishes quickly does not mean that they have answered correctly!
Consider teaching the use of a calculator and sending your child to the test with one. Calculators can be used on the math tests except for the estimation problems in grades 3 through 8. Students (one or all) may use a calculator. This is different from the past where everyone had to have "access" to a calculator if anyone used one.
Remember that children have a broad range of abilities and skills. Taking a standardized test under timed conditions is a skill that is much easier for some children (and adults!) than it is for others. The Iowa Tests do not measure intelligence, but are a measure of how your child performs certain academic skills in a timed environment. Some children thrive under these conditions, but others do not. You'll need to balance the results of the test with what you know about your child's personality and learning style.