Number Sense: An Internalized, Visual Process
I'm excited to have learned that the part of our brain that provides number sense, an internal numberline, is created by the visual processing centers. If there is any insult to the part of the brain that processes vision (in the case of some visual impairments and neurodivergence that shows up as learning differences), a person may not experience an internalized number sense.
I love that our acupuncturist says, "Yep, some bodies do that. That can happen." It's so accepting! Seeing how people learn is such a beautiful and fascinating thing, and in homeschool, there's a similar sentiment, "yep, I guess some brains do [fill in the blank]." This spring's version for me: Some brains will require tangible, external representation of the spatial relationship between numbers. I shared a project that supports this in a study group I joined. It was one of those projects that was fun, but more important was what it let me see about how my kids need to learn. I love a project that changes how we think about what a person can ask for and expect to meet their learning needs.
The full article includes ideas generated by many participants in the group and a link to a video about how the brain processes math and how that's relevant in the case of brain-based visual impairment.
“My 12-year-old CVIer benefits from a tactile representation of number lines. She had such a hard time visualizing the number line. And we’ve learned from Matt Tietjen’s presentation that visualizing or imagining math is a part of learning math concepts. When I saw how helpful a tactile approach was for her to internalize and understand a number line, I thought about her challenges with timelines.
She loves history, and we’ve had a long piece of paper with the centuries on it in the kitchen for years. When she learns something new, for example about the Vikings, I show where it occurred on the timeline. After our first CVI and math discussion, I gave my daughter beads and told her each one is one hundred years. She strung them onto a necklace and used her strong verbal and tactile skills to talk through what it meant to have a first century, second century, and so on, and then one hundred, two hundred, three hundred years, and so on. She was very excited to make the connection that had previously eluded her: the fifth century contains the years that are in the 400s. She relies on verbal and auditory skills to memorize things, especially abstract concepts, and the words “fifth century” and “four hundreds” were very confusing. She had also never really understood what the words “twelve-hundred” meant in numbers, or where on the timeline to find a word-heavy number like “sixteen twenty-seven.”
As soon as we explored a timeline with beads as centuries, I realized she did not know there was the same amount of time between the years 0 CE and 1000 CE as between 1000 CE and 2000 CE. She had based her understanding of the timeline (number line) on the one we had made in our kitchen, which is visual and has more physical distance between 1600 and 2000 than the rest of “time” (we have more historical events to fit into this time period, so it is expanded). Touching the beads, she was amazed to see how recently our country was founded, how long the Roman empire lasted and posed questions about how many years existed before the year 0 CE.
We have discussed these topics for years but she had nothing to hang the information on—no internal number line. We then spent a week making bead strings that are large enough to feel each century easily that she references now. I can pause a documentary and we take our time touching the timeline beads to find where an event approximately occurred. My daughter is relieved and excited to have this tool to understand timelines. My typically-sighted kid also loved this project.”
Read the full article: "Math and CVI: Ideas for a multisensory approach" at Perkins School for the Blind