Elementary teachers workshop Day 1.
We began the workshop with a common exercise that engaged us as active learners.
Exercise 1. Using colored markers and large post-it notes, mark the heights of all workshops participants and list their names next to the marks.
Exercise 2. Write a paragraph or two about the exercise.
- REFLECTION: Think of the exercise as an event and reflect on what you did. Describe what you did.
- DISCUSSION: Discuss among yourselves, and talk about what you did.
- WRITING: Write a pararaph about what you did.
- READING: Read it aloud to each other.
We used 1" squared large Post-It wall chart paper, and attached to the wall. A line was drawn down the middle of the page. One person served as the "measurer", and with coloured markers, marked off the height of each person in the room.
I am in the middle of the group, and tied with Carol. Ron was the tallest, and Mary Lou the shortest. The difference between the tallest and the shortest person in the room was 12 boxes, which is 12 inches. Mary Lou is 1 foot shorter than Ron.
Making Connections: Explicitly connect children's everyday language to the more formal rigid language that is the literal translation of the symbolic algebraic/math language .
Exericise: Have 2 people of different heights stand and have audience/class observe and discuss the differences. Create/Write 2 sentences about these 2 people that explain/make explicit these differences.
(a) Ron is taller than Dawn
(b) Dawn is shorter than Ron.
What is the feature that is being talked/written about? Answer = Height
Write 2 more sentences but include the word height at the beginning of each sentence.
(c) The height of Ron is greater than the height of Dawn
(d) The height of Dawn is less than the height of Ron
What words are included in the second pair of sentences that are found in "mathematical language"
Answer = "Is greater than" and "Is less than".
Do those words "Is greater than" and "Is less than" convey information about the feature that is being compared/discussed? "Is greater than" and "Is less than" could be used to describe the weights of these two people, the length of their hair, the size of their feet...anything.
Notice that in this formal mathemtatical way of expressing oneself, there is an explicit decomposing of "is taller than" to include specfic language to express the feature "height" as well as the subjects of the sentence about whom we are interested in.
Problem solving in mathematics requires that we extract all of the pertinent information to be able to solve the problem. This requires a level of specificity and an attention to detail that is not normally present in every day language. He's taller. Spoken language has a brevity to it that is annoying when not used.
Mathematical language uses the extended version of the language. "He's taller" is enough in spoken language because there are other pieces of information that are being transmitted through other senses. Maybe an inflexion in the voice, a nod in the diretion of the person being spoken about etc. In mat, "he's taller" does not convey all of the information needed. We need to know that there are 2 people being compared, and that the feature or attribute that is being talked about is height, not weight, not age, not pigment etc, etc. Therefore we have a very formal stylised way of expressing the information which can then be translated into algebraic symbols.
(e) The height of Ron is greater than the height of Dawn
(f) The height of Dawn is less than the height of Ron
Who in the world walks around expressing themselves in this way? The same information in sentences (e) and (f) is transmitted in sentences (a) and (b). There is no need in every day language between people, to be that rigid or formal in trying to convey the information about the differences in height between Dawn and Ron.
But this rigid formalised language is the implicit albeit latent link between spoken everyday language and the symbolic language of algebra and mathematics.
Moving on from the rigid formalised sentence structure of sentences (e) and (f), we can create symbolic representations ( short hand symbols) for each of the components of the sentence.
In the classroom, children have the opportunity for artisitic expression creating their own iconic symbols to represent themseleves, their classmates, the features being discussed and the relationships being expressed. I am using the fonts available online to create my symbols.
- Create a symbol for Dawn: Here is my symbol d
- Create a symbol for Ron: Here is my symbol m
Translating the everyday language sentences (a) and (b) to symbolic language we now have
(a1) m is taller than d and (b1) d is shorter than m
We need symbols for "is taller than" and " is shorter than". This is different from the conventional mathematical symbols that we could use to represent " is greater than" and " is less than". The phrases "is taller than" and " is shorter than" contain information that is not included in the phrases "is greater than" and " is less than".
So my symbol for "is taller than" is 5 and " is shorter than" is 6
Translated to a symbols, Sentence (a) now becomes m 5 d and sentence (b) d 6 m
However, the rigid formalised language of mathematics extracts the feature, in our case height, from the everyday common usage of "is taller than" and " is shorter than", and places the word or icon for height next to the object that it is describes. An adjective if you like, ....adjectives in algebra... there's an insight.... so an adjective must describe a noun... height must be attached to either Ron or Dawn .
To translate the more formal sentences (c) and (d) into symbolic language, we need a symbol to represent height.
Create a symbol for Height : Here's my symbol . Translating sentences (e) and (f) into my symbolic language we get:
(e1) . m is greater than . d
(f1) . d is less than . m
I can now replace the words " is greater than" and " is less than" and use the conventional math notation for " greater than" > and "less than" < .
(e2) . m > . d
(f2) . d < . m