Creating Decimal Charts
Lesson 2 of 5
Objective: SWBAT use decimal notation for fractions with denominators 10 or 100.
Today's lesson built upon yesterday's lesson, Decimal Introduction.
Goal & Lesson Introduction
I began today by reviewing the goal: I can use decimal notation for fractions. I explained: Yesterday, you learned how decimals and fractions can be used to represent the same amount shaded in a hundreds grid. For example, (I wrote the following on the board) 0.5 is equal to 5/10, which is also equal to 50/100. For the first part of today's lesson, you will be working with your math partner to further explore how decimals and fractions can name the same shaded part.
Picking math partners is always easy as I already have students placed in desk groups based upon behavior, abilities, and communication skills. Before students began working, I asked them to discuss how they would like to support each other today. I gave them many examples: Do you want to take turns talking out loud? Do you want to solve quietly and then check with each other? Or do you want to turn and talk anytime you get stuck? Students always love being able to develop a "game plan" with their partners!
I passed out copies of these Model Cards, found at Virginia Department of Education, to each set of partners. I asked students to begin cutting out the cards. I also passed out one piece of construction paper to each group and asked students to make four column with the following Column Headings: Decimal Numbers, Written Form, Area Model, and Equivalent Fractions.
As a side note, by including the area model cards in this process, students engaged in Math Practice 2: Reason abstractly and quantitatively. I didn't want students to just memorize 2/100 = 0.02. I wanted them to see how 0.02 is the same as 2 squares colored in out of 100 which is also equal to 2/100!
Creating Decimal Charts
Next, I modeled how to match the model cards and place them in a four-column chart on a piece of construction paper. Here's what the end result will look like: Completed Decimal Chart.
During this process, we found that it was easiest to start with the area model first and then find the matching decimal number and written form cards.
Monitoring Student Understanding
While students were working, I conferenced with every group. My goal was to support students by providing them with the opportunity to explain their thinking and by asking guiding questions. I also wanted to encourage students to construct viable arguments by using evidence to support their thinking (Math Practice 3).
- Can you explain what you know?
- What step did you take first?
- What pattern did you notice?
- Does that make sense to your partner too?
- What are you thinking?
- Can you show me your thinking?
- Can you find another equivalent fraction?
I found that the most challenging part of this activity was finding equivalent fractions so I made this my focus when conferencing with students: Finding Equivalent Fractions.
Here, two more students are developing a understanding of the connection between fractions and decimals: Finding More Equivalent Fractions.
Fraction & Decimal Values Practice
Next, I modeled how to label each area model with a fraction, decimal, and written form.
Again, during this time, I conferenced with as many students as possible: Identifying Fractions & Decimals.
Here's an example of a student's work: Completed Page.