In education, math especially, there exist a learning situation I call the patting head and rubbing belly phenomena. In this phenomena students are presented a math problem that consists of several steps they know how to do and then maybe one or two additional steps that are new. Adding the additional step is like adding the task of patting your head while you rub you belly. Many students will struggle with this.
Adding one additional math step to a sequence of steps that are prior knowledge or the students seems so simple. What actually can happen is the entire effort becomes challenging. This is true for all types of math, whether it is the general curriculum or life skills/consumer math.
I have written about how we cut up a hotdog for a baby in a highchair and that we could do the same for math topics using a task analysis and chunking approach. Related to this, I recommended that support class be used not to backfill gaps but to address prerequisite skills for upcoming or current math topics covered in a general ed math class.
This phenomena plays out in life skills math or consumer math in a stealthy manner because the steps or tasks seem so simple. For example, many of us have worked with a child or student who was learning to count money. When learning about a nickel or a quarter, the coin name and value are easily identified. Once both are introduced, many students confuse the two and may even freeze while attempting the work with the coins.
There is an ABA based process for addressing this using a task analysis and chaining in which steps are worked on in isolation before connecting (chaining) the steps together (and not all of them at once until the end). One related strategy to help implement this approach is through scaffolded handouts in which the steps are enumerated and the structure of the handout isolates the tasks. I have used this approach for 1 to 1 correspondence up to AP Statistics (see below).
When working out a draft of an IEP, I suggest having the task analysis and chaining explicitly identified in the accommodations page and ask for an example of what this looks like (using an example math topic).