Thursday, August 26, 2010

Sample Science Lesson

Before wrapping up the knowledge of the universe (two more topics: natural history and physical development left), I thought I'd share how I do science lessons. The most ideal situation is when you know your learner. I know that Pamela has a strong eye for pattern and takes a long time to pick up new vocabulary. In the math worksheet below, notice Pamela wrote the years 2010, 1982, 1954, and 1926. She knows that all four of these years are a common year starting on Friday. She has all fourteen possible calendars memorized and know what years go with what calendar. If given a month, day, and year, she can tell you the day of the week in a few seconds. That is how good her eye for pattern is!

Pamela spots simple patterns effortlessly In math, we covered dividing an equilateral triangle into nine triangles (RightStart Intermediate Geometry Lesson 7). She had no problem filling out the second column. As soon as she finished the third column, she said, "Odd." I wrote equal signs to the left of the odd numbers and asked, "What do you do to get from the second column to the third?" Within seconds, Pamela replied, "Subtraction. Minus 1."

You may notice the writing on the side. Because Pamela has a hard time with vocabulary, we reviewed shapes with three to six sides. If I do not find ways for her to use new words every day, they will not stick. Seeing them and using them helps to transfer them into her memory.

The other day we did a lesson from TOPS Electricity 32 in which we explored what kind of circuits will and will not power a light bulb with a dry cell (sh . . . it's a battery . . . the teacher is supposed to say "dry cell"). Everything depends upon hooking up four contact points properly: the positive and negative terminals on the dry cell and the metal tip and the silver siding on the light bulb. In the previous lesson last week, we identified the four contact points in our exploration.

At the beginning of a lesson, I try to assess what she remembers. Why? For us to store a new memory, we need to anchor them to a previous memory. Otherwise, the new one will have nothing to latch it and will drift off into Never Never Land. Even better, if you feel a strong emotion, your brain will store the memory with superglue, which is why Charlotte Mason encouraged the reading of living books, not textbooks. In the RDI world, we call this creating a personal anchor.

I added clip art pictures of a dry cell and bulb to the record sheet to see if Pamela remembered the contact points. She did not. So, I had her study her own drawings from the previous lesson and add arrows to the contact points on the clip art pictures. Pamela has such a great eye for pattern that, during the lesson, I figured she would probably quickly realize that you must have four contact points connected if we made a point to count them.

Sure enough, the first three predictions were spotty because she had not fully understood the point of drawing contact points. However, by the fourth circuit, the light went on (pardon the pun) and Pamela predicted the rest of them correctly. (We went out of order going left right rather than down one column and the next: we did A, D, B, E, C, F.)

We had enough time to squeeze in another lesson, this time on hooking up dry cells in a series. Pamela had so much fun with this one and quickly caught on to the connection between the number of cells and the brightness.

Dim

Medium

Bright

She also saw how having opposition in two dry cells prevented the light from working. At first, she did not see the connection between hands-on (the dry cells) and diagram. Once I highlighted them, she saw the difference between opposition and not in opposition. Where we both got confused was having two dry cells in opposition and one not. That moment reveals the beauty of homeschooling. The teacher is not the source of all knowledge and does not have to know every thing. Teacher and taught can learn together.

Opposition
Luckily, there is an engineer in the house. Since we both were confused, we are going to explore this a little more before moving onto the next lesson. I consulted the resident expert, Steve who has a master's degrees in electrical engineering and once built his own calculator that could only add. I emailed him with questions and he wrote back,

DC batteries are like small streams of water. If you have three streams going in the same direction, feeding the next one, then flow is stronger and hence the bulb is brightest. If you have two batteries going in one direction and one going in another, fundamentally two batteries are pushing against one, and hence the end result is that the net flow is equivalent to one battery (not including heat losses).

I can't wait to share his analogy with Pamela! If Steve had taught me electrical engineering in college, maybe I would have remembered something . . .