Give me 100%.
Lesson 20 of 25
Objective: SWBAT model percents on a grid and find fraction and percent equivalencies.
The students will be looking at a problem involving a Hershey Bar. In case some students have never seen a Hershey candy bar, it may be a good idea to have a visual for them. I’m going to have the students draw their own picture of a Hershey bar with 8 equal sections in their notes under the section titled do now. Then I’m going to ask the students what is equal to 100% of their candy bar, 50%, and 25%? This will give me a good indication of their knowledge of percentages. If students have difficulty with this, it is ok to move on. We don’t want this to be the focus of our lesson. When students have come up with their amounts for 100, 50 and 25% have them share their answers with their shoulder partner. Students should be discussing how they came up with their answer by using mathematical language (SMP 3).
During this section, I’m going to have the students modeling percents on a grid. As I'm modeling for them, they will be taking notes. These notes are prepared by me to follow along with the instruction. Many times, students have difficulty understanding that 100% = 1 whole. Modeling is a great visual to help them understand this concept. Begin the discussing by talking about the grid. Ask the students to tell you how many squares are in the grid. Allow time for some thinking and then take some responses. Be sure to have students explain their reasoning. (SMP 2). When you have established that each piece is worth 1/100 (and I would write it like a fraction because we will be using this later) which is equal to 1%, you can go through each slide having the students model what each percent looks like. Additionally, I want the students to tell me what it means. I’m looking for students to say 75% means 75 out of 100 or 75/100. By relating percents to ratios and fractions you are getting students to understand a pattern (SMP 7).
Modeling % Round table
There are 8 problems in the Roundtable that require students to model or write the percent from the model. Right now, there are no percents over 100% as the focus is to get them to understand the part to whole relationship. (SMP 1 and 2)
During this portion of the lesson, the students will be looking at percents or ratios and finding their equivalencies. I’m going to have the students model the percent, explain what it means, then put it in a ratio table to find its equivalent ratio. Students will use their notes to keep track of their learning. Some students may use the numerator of any fraction for the percent. Modeling and using ratio tables will help to eliminate this misconception. This will be modeled throughout the rest of the instruction. For each slide, I want the students to model the percent or ratio. I’m confident that this will help students when having to justify their answer. For example, one question asks if 3 out of 10 is a passing grade. The students will put the ratio in the table and find the percent equivalence, then they will shade in the model. Students can say, “If the whole grid is the test and I have less than ½ of the grid shaded in that means I did not pass the test”. Again, we want them to make connections about the relationship. (SMP 7)
There are 6 problems for this round table. The students will be following the model from the direct instruction. They will be modeling, writing, and explaining what it means for each question.
The students will be working on a connect 3: ratios, percents, and fractions. On each line they need to make the connection. In the middle they need to summarize the learning for the day in a couple of sentences. If time permits, have the students compare/share answers with a partner. Otherwise, do this as a whole group discussion to make sure everyone has seen the relationship and to find out if there are any misconceptions.