Here’s how I sequence my lesson to develop pupil’s understanding of the meaning of the equal sign. Actually the lesson uses the context of the meaning of equal sign to introduce the students to the meaning of variable intuitively. The students enjoyed this lesson and they said they loved the way I made them think. Scaffolding was done through questions that engages pupils in reasoning and making decisions. Note that the emphasis of the lesson is not on computations but on thinking and problem solving. This is also an example of teaching algebraic thinking in the grades.
I first wrote the equal sign on the board then said What does the equal sign mean? You may use an example to explain your answer. One boy said it means you add or do the operation and provided this example 2 + 10 = 12. I asked the class who agrees with him and 25 out of 35 showed hand.
What about in 15 + ____ = 21 + ____? One girl said “It means balance” and explained that 15 plus a number balances with 21 plus another number. When I asked the class who agrees with her 30 out of 35 raised their hand. Everyone’s eyes was on me, waiting for me to say which meaning of equal sign is correct. I just gave them a wink to heighten their curiosity.
Now that I got them all thinking, I asked: Do you think you can put just any two numbers in the blanks? With this question I successfully divided the class into two camps: those who say yes and those who say no and everyone is challenged to prove themselves right or prove the other wrong.
Click here for the slide version of this post.