Talk with your child's math teacher about his or her condition. Explain that dyscalculia is a serious learning disability, he isn't trying to get out of work and needs special attention.
Explain that your child may need to take tests one-on-one test. Having an immediate response to whether or not a problem has been answered correctly can help your child determine whether she has just read the numbers incorrectly or did the math incorrectly.
Explain that problems written too closely together get confused just as words can get confused for a dyslexic person.
Work with your child's teacher to develop a teaching plan that helps take these considerations into account.
Create a real-world, language equivalent when introducing a new math term or concept. Remember numbers are like a foreign language to students suffering from dyscalculia.
Be consistent when using formal and command math terms. Add, subtract and multiply are command terms. Students suffering from dyscalculia may become confused later when they encounter formal terms like sum or product. Use a combination of both terms consistently so your students understand they mean the same thing.
Teach reverse word problems. Students always learn how to solve word problems by translating paragraphs of text into a simple math problem. For example, a student will solve "John had four apples and lost three; how many were left?" by writing out "4-3=1." It is equally important to let students with dyscalculia start with the "4-3=1" and work backwards to create a number story.