Special education students will struggle in math for one of three reasons.
1. The student has not mastered the skills required to do the math.
2. The student is unable to keep up with the pace of the class.
3. The student is a concrete learner and needs direct instruction in a rule based method curriculum.
Here's one idea for a modified lesson.
Have a worksheet available instead of using the text. Have 2-4 problems that the general education students are doing. Each problem is written twice. One with all the steps and answer provided. The student simply copies the steps and answer to the problems. The student is given access to and exposed to age appropriate instruction. The remaining work should be focused on the IEP goals. I suggest having a mixture of mastered skills and new skills at the student's learning level. This encourages independence and confidence. It also allows the paraprofessional to help other students in the class.