Fractions Make a Come Back
Lesson 1 of 19
Objective: SWBAT add and subtract fractions and decimals by working in pairs (no borrowing in subtraction).
Students enter silently according to the Daily Entrance Routine. They are given 10 minutes to complete their Unit test from the previous day if they were not already finished.
For students who have completed the test, they are asked to follow the directions for the “Do Now” indicated on the SMART board and then take out a book to read quietly.
The directions read:
1. Take out a blank sheet of paper.
2. Write a full heading. (name, date, class)
3. Copy the AIM: KWBAT add and subtract fractions and decimals
The first group activity that we will complete today is to begin copying the notes from the SMART board, leaving blanks where appropriate (see Day 20 - Notes). The notes read as follows:
- When we add and subtract fractions, we have to make sure that they have the same ____________. After we get an answer, we should always ___________.
- If the fractions have the same denominator, we add the numerator only and leave the denominator the same.
- If the fractions have different denominators, we have to:
- Find the LCM or LCD
- Convert each fraction so that it has the same denominator
- Solve and simplify
Decimals: When we add and subtract decimals, we have to ______________.
The blanks are to be completed together after students have been given an opportunity to copy the information.
Teacher's Note: One of my aims is to expose students to as many different note-taking experiences as possible. Sometimes I will have their Cornell Notes already set up and printed. Other times I think it is valuable to have the experience of setting up their own notes.
I also plan to complete a series of fluency skills to warm up and review for the task. The examples include:
Equivalent Fractions –
- ¾ = ?/12
- ?/8 = 6/24
Word Problem –
- The price per share of stock on A-Plus company was $54 6/8. It rose by $3 5/8. What is its price per share now?
Adding and Subtracting Decimals –
- 81 + 31.75
- 52.7 – 0.07219
Task - Partner Work
Students are asked to work in pairs for ten minutes of class to complete Day 20 - Task - Fractions and Decimal. As they work I urge my students to continually consider “what is this problem asking me to do?” I find this to be especially important when my students experience frustration. When students misunderstand a problem, I provide them with the following questions to guide them to persevere and figure out the problem (MP1):
- What are we trying to find?
- Can I use numbers to represents different parts of this problem?
- What model can I draw to help me visualize this problem?
After about ten minutes, I will ask students to enter their answers into the Senteo clicker (PRS) so that I can gather data about their performance on these problems.
Today, I will close the window for entering answers into clickers 10 – 15 minutes before the end of class. I usually give my students a 5-minute warning about the closing of the window. After I give this warning, I monitor the rolling results for each question, identifying the three questions we should discuss as a class. Then, I will have students who finish early write their answers to the chosen questions on the board. We'll review their work on the board as a class.
Cycling back to the notes, I select more students to explain HOW they solved a particular problem. These students are selected based on their performance during the "task" section of class. During that time, I am flagging students I will want to cycle back to during the closing to either check for understanding or to explain how they solved. Some students have cleared ways to communicate these steps than myself. For example, one problem we are likely to review is #9 since it involves a word problem and changing denominators to make them "alike". Review of this answer would go something like this:
Teacher: (After one student reads the problem) Can I get another student volunteer to review the solution? what did you do first?
Student: I lined up the numbers to subtract them.
Teacher: How did you know you needed to subtract? and how did you line them up? horizontally? vertically?
Student: I lined them up vertically, and I knew to subtract because it says "she spilled"...
Teacher: Good! Now talk to me about your subtraction steps. Are the denominators in the original problem alike or not alike?... how do you get them to be alike?... what must you find?... what is that called?
Student: (goal answer before moving on to the next question) the LCD which was 8...
At this point if the student says 16 instead of 8 it would be a great opportunity to ask if anyone used a smaller LCD and why it might be better to use a smaller LCD... its also a good idea to run through both solutions, using 16 and 8, to show students that the answer is still the same, provided simplifying is included and also completed correctly. Where I take the conversation at this point really depends on the discussion and misunderstandings observed during the task. Whatever helps most students is what I push students to share.
Here is tonight's Homework - Fractions and Decimal.