For today's Warm-Up, I will have my students complete three problems that I will use to assess the pre-requisite skills necessary to successfully master the concepts taught in this lesson.
In my opening exercise, my students will be using 10 by 10 grids for the purpose of practicing how to represent decimal quantities in the 10ths place and 100ths place.
In order to show that they understand the concept, the student will have to do the following:
Once again, like the warm-up, this opening exercise assesses prerequisite knowledge that is necessary to master the concepts and skills surrounding adding and subtracting decimals.
Using the opening exercise, I will facilitate discovery concerning the following:
During the facilitation of this lesson, I will review place value as well as the difference and locations of whole number quantities versus decimal quantities. I will be sure to pose the question “Why is there no one-ths place?” The answer that I am looking for is “because once you reach one you are now in the whole number territory.” I am also looking for students to discern that each place value is either 10 times more or one-tenth of the place value next to it depending upon its orientation and assuming all place values are represented with the same digit.
Ex: 2,222,222.222222
Students should recognize the ones place as a point of reflection.
Helpful Instructional Videos (LearnZillion):
Adding Decimals Using Base Ten Blocks
Subtracting Decimals Using Base Ten Blocks
To show that they understand what was presented during instruction, I will have my students complete three problems then the class will go over the three problems as a transition into exploration.
1. 4.679 + 2.34 =
This problem is to be used to check simple calculation skill.
2. 72 – 0.479 =
This problem is to be used to check student ability to annex zeros and regroup using zeros.
3. Kevin needs three wooden boards to repair his porch. The lengths he needs are 4.12
meters, 2.5 meters, and 2.25 meters. He purchases a board that is 10 meters long and
cuts the three sections. How much of the board that Kevin purchased will be left?
This problem is to be used to check student ability to problem solve.
During this time, the students will complete the exploration individually but, later they will be given an opportunity to confer and share with a peer.
Problems for Exploration:
The students will solve problems 1 and 2 numerically and then they will explain their method in words and provide a complete answer.
Students will solve problem 3 by writing a brief essay.
3. Jeremy found the answer to the following subtraction problem 74.6 – 9.73. His answer was 65.13 which is incorrect. Write a brief statement to Jeremy explaining his mistake and providing him with the correct answer and method to solve this problem.
At this time, the students will be provided with 7 minutes to confer with their group (my classroom is set up into groups. If you do not have your classroom set up into groups, you may have to provide transition time for them to get into groups or with partners). Before student confer, I will have already provided a written display of expectations during this time of conferring and posted these expectations where all of my students can see the expectations and understand the consequences for not meeting those expectations.
Expectations:
The students will then be given an opportunity to share their discoveries. Each question will be critiqued. A group will be selected to present a problem selected by the teacher. Then, the teacher will allow discussion of that problem to commence. Each question will be allotted a time limit of no more than 4 minutes for presentation and discussion.
After presentations, the students will complete the ticket out the door which should already be in their possession. The ticket out the door will be a single word problem students will answer and give to teacher on the way out. It is necessary to prepare the "tickets" prior to students entering the classroom by cutting out the "tickets" from the provided document.
TOTD: Jeff has two bills in his pocket and no change. He wants to buy a shirt for $12.98 and a pair of shoes for $54.69. What is the least amount each bill could be worth in order for Jeff to be able to purchase the items he wants?