# Mathematical Musings

Today, I planned and co-taught a lesson to 6th graders about decimals. As an introduction, we had them place some numbers in order from least to greatest – partly to get them working in small groups, and partly to see what we have to work with in terms of what they already know about decimals (having just finished a unit on fractions). Several of them expressed displeasure at this, particularly when confronted with the challenges of deciding whether 0.5 or 1/2 is smaller and where to place 0.3 and 2/3. The complaints centered around things like “I am never going to use this!” “Why do we have to learn this stuff?” and “I will just use my calculator.”

Once we moved further into the lesson, the complaints shifted slightly – the focus of today’s lesson was to practice using benchmarks to estimate sums and differences. Now, the students were upset that they couldn’t just do the math to find the answer – that we were expecting them to actually *estimate*! You know, in case they are ever at the store and trying to decide how many bags of candy they can buy with $5, or whether they can afford that iPad yet….

Tonight, I am sitting at home, enjoying a fantastic fall storm, pondering various knitting related things. The thing I keep coming back to is how useful math has been when it comes to knitting. Decimals and fractions are endlessly useful, and despite what people warn about gauge and precision and accuracy, estimation can be quite handy as well!

So – what mathematical concepts do you use when you knit? Or do you avoid knitting anything that might require even the slightest hint of math beyond simple counting?

I used a spreadsheet for converting yards to meters when calculating yarn requirements while working with American patterns/Norwegian yarn.

Also, I use a spreadsheet for calculating when dealing with different yarn weights in relation to the weight recommended by the pattern. Recently, I made a hat which was spot on for the number of stitches cast on/size, but I had forgotten to take into account the fact that the row height was less….

I’ve mentioned before that math makes me cry, and that fact frustrates me the most when it comes to knitting. I can generally puzzle out very basic gauge math and might be able to muddle my way through upsizing a sweater, but that’s really where I draw the line. Even then, I’m happiest if I’m given blanks to fill in and all I have to do is measure and count.

If I ever really wanted to knit something that required math, I’m sure that I could work it out if I recruited some help, but math just makes me so anxious that I generally avoid it. As I’ve grown older and gotten farther away from school, I’ve realized that a lot of my problem is that I don’t understand WHY I’m doing what I’m doing. To use a very over-simplified example, I was taught that .5 was bigger than 1/4, but it was just a fact that I memorized, so I couldn’t apply the logic behind it to anything else. I don’t know if it was a new math/old math thing, or a class structure thing, or just truly bad luck with math teachers, but it wasn’t until I was taking high school algebra as an adult that I found a teacher who could make it make any sense at all–and it was because he was explaining the logic as logic and not as rules to memorize.

I feel bad for your students, because I remember the deep frustration of just not GETTING IT, especially when other students were, and being sure that there would be ways to avoid using math (like my trusty calculator) in the “real world.” If I knew back then that I might want to write a sweater pattern now, I might have fought harder to understand.

Doubt that this qualifies as a mathematical concept; but I seem to use the trial and error concept pretty regularly. Also know as knit and frog and reknit.