Everything was going well in the beginning of the lesson with the DO NOW of subtraction and addition. This had been a topic they had just been tested on and everyone was able to do these problems. However, when I introduced the multiplication with whole numbers and the multiplication with decimals, they were able to do the multiplication problem without the decimals, but they were all confused about the numbers with decimals.
Some of the students performed them with ways that I had anticipated, like lining up the decimals, and other students attempted in ways that I could not understand. What threw me off during the lesson was the fact that many students could not work out long multiplication. Many of the students were using a lattice system of multiplication, and I had not prepared to use this system with decimals.
I had to quickly readjust everything in order to accommodate the students’ lack of ability to do multiplication. I had to quickly change the samples to easier numbers. I had paid special attention to selecting problems that were easy to multiply, and I thought they would be able to handle the problems I had chosen. I did not want to emphasize their multiplication skills, but rather their ability to understand the concept of multiplying with decimals and the procedures they need to follow. However, I was taken aback by their lack of skill with long multiplication. We had to provide them with additional homework in order to reinforce this.
I definitely learned that no matter how much you prepare and anticipate issues that may arise; you never know what is going to happen. In addition, I learnt how to quickly readjust an entire lesson. Overall, the majority of students understood the concept of multiplying decimals, and demonstrated what they learned. Since this was their first lesson on multiplying decimals, I was pleased with the fact that many students were able to understand. Follow-up lessons will solidify their understanding.
If I were to do this lesson again, I would not have started with the addition and subtraction of decimals. Originally, I was not going to do this, but on the suggestion of the teacher I did. However, I believe that it confused the students more because of the way you have to align the decimals in addition and subtraction.
Instead of comparing the multiplication of whole numbers and decimals, they were comparing the multiplication in decimals to the addition and subtraction of decimals that I had just made them perform. Next time I would only introduce the two multiplication problems: one with whole numbers and one with decimals. In this way, the students can compare the multiplication steps with whole numbers and decimals. I’m not sure if that would work, but it definitely was my first instinct.