In this Adding Whole Numbers Video, I introduce the lesson for today.
In this lesson the students add numbers to the hundred thousands with and without regrouping.
In past lessons, we learned about place value. The students learned the different places on the place value chart and the value of those places. In today's lesson, the students add numbers according to place value. They use manipulatives to help get a visual and conceptual understanding of adding with and without regrouping. I open the lesson by posing a problem for the students to think about. "There were 458 students in our school last year. This year there are 73 additional students. What is the total number of students in our school this year? Let's find out."
The students work at their desks during our direct instruction. They have a place value chart and place value blocks on their desk. I want the students to work along with me as I go through the power point. Using a place value chart and blocks gives the students a visual understanding of the concept. I feel that if the students can add with manipulatives on a place value chart, then they get more of a conceptual understanding.
I start out by letting the students know that today we add using place value blocks. Once we learn the skill with the place value blocks, then we add using paper and pencil. I begin the lesson with the following problem: "There were 458 students in our school last year. This year there are 73 additional students. What is the total number of students in our school this year? Let's use our place value chart to find out."
The students must begin by placing the numbers from the word problem on the place value chart. They see how to do this in the Adding Whole Numbers power point which is on the Smart board. I remind the students that the largest digit that can go in any place is a 9. If you have a two-digit number, you have to regroup.
I explain by saying the following: First begin adding in the ones place. 3 + 8 = 11. Because it is a two-digit number, you must regroup. (The students should take 10 of the ones blocks and replace it with a tens block.) Put the remaining 1 in the ones place. Next, add the tens place. Add 7 + 5, which equals 12. Do not forget to add the 1 that was regrouped. Therefore, you have 13. This is also a two-digit number. Take 10 of the tens blocks and trade them for a hundreds block (10 tens equal 100). There will be 3 tens remaining. Last, add the hundreds place. You have 4 in the hundreds place plus the 1 that was regrouped. 1 + 4 = 5. You answer to this problem is 531.
Last, I have the students work the problem with paper and pencil. They must show the regrouping as they add.
The students continue practicing the skill with a partner. Each group is given the Adding Whole Numbers Group Activity sheet to solve. They must first solve the problem by using the place value chart and blocks. Then the students must use paper and pencil to add the problem. Their addition problems with paper and pencil must show regrouping if it was necessary.
By working with a partner, it gives the students a chance to collaborate with another person. I partner the students according to their levels. I want my higher level students to work with students that are lower level. They are an excellent resource for the lower level students.
As the students work together, I monitor their progress. If the students are having a difficult time, I ask guiding questions to help lead the students to the answer.
1. What is the largest digit you can put in a place?
2. When you have a two-digit number, how do you regroup? Show me with the place value blocks.
3. In which place do you begin adding?
4. How does adding with place value blocks help you add with paper and pencil?
This is a sample of Student Work - Adding Whole Numbers.
Early Finishers: Any students that finish the assignment early can practice the skill on the computers at http://www.math-play.com/Addition-Game.html.
After the students finish their group activity, I have the students complete an independent assignment. This is to find out what each individual student has learned from the lesson. The students need a piece of paper and pencil for this assignment. I have the Write to Explain (Adding Whole Numbers) assignment on your Smart board.
Write to Explain:
238 + 153= _____.
How can using a place value chart and blocks help you solve this problem?
To close the lesson, I take volunteers to share their answers to the independent assignment. This is an another opportunity to reach those students who did not quite master the skill. I use my interactive place value manipulatives for the Smart board to work the problem along with the student as they explain to the class. Once again, providing a visual for the students to gain conceptual understanding.