Same As Subtraction 3, 4, 5
Lesson 7 of 9
Objective: SWBAT solve subtraction problems with like differences to 5 by solving, cutting and pasting the equations in the correct columns.
Daily calendar provides and opportunity for kids to practice rote counting to 100 by 1's and 10's and to 20 forward and back. It is essential for kids to be able to count backwards as it builds a number sense that would otherwise be thwarted without it. It promotes subtraction understanding and the subitizing of adding and subtracting by one.
We use an ActivBoard for calendar and counting practice. Before I had an ActivBoard, I used a standard classroom wall calendar and counting posters/pocket charts. We still made it fun and exciting. With the videos we sing, dance and exercise while counting. This ensures participation and the kids learn faster when they are enjoying themselves.
We use the calendar found on Starfall (It's free. There is a fee for the extended site use).
Here are the counting videos we use for this lesson:
Counting to 20:
Countdown from 20:
Count by 10's to 100:
Count by 1's to 100:
Since we are in that time of year when we bridge over to first grade, I have added counted by 5's to our daily counting practice:
To begin this lesson, we review (through discussion) what subtraction is and what it means. We practice subtraction fluency 0-5 using our fingers. Each problem begins with us holding up 5 fingers and me shouting out "minus ___". The kids quickly put that number of fingers down and yell out how many are still standing. The goal is to get them fluent with subtraction using numbers 0 to 5. (Insert CC here).
We then sing our subtraction song using the video, "When You Subtract with a Pirate":
Why do I use the same song every lesson for subtraction? Because the kids memorize it and begin to sing it as they work. We go over the song and discuss what each part means and build a conceptual understanding by it. When you use too many resources, the kids can get confused and too much information begins to get stored and then it becomes muddy in their minds.
I introduce today's activity by reminding them about what we did yesterday. They connect quickly to the activity as I show them how it's exactly the same, just the equations are a bit more challenging.
I model a couple of problems to ensure they remember how to do it and to show any absent kids how it's done.
Since they are so comfortable with the format of this activity, the guided practice is very limited an done quickly.
I have the kids sit at the tables while the helpers pass out the supplies. One everyone has all their supplies, I have every kid solve only the first problem. I ask them to hold up their pencil when they are done. Once all pencils are up, I have them yell out the answer they wrote down. Then I have them cut it out and paste it in the correct column.
It appears that they are ready to take on the job for themselves so I roam the room and monitor progress, assist individuals and ask open-ended questions that force them to explain their thinking and defend their chosen answers.
This kids are capable of running the show on this lesson now that they are competent to complete it on their own.
I roam to monitor solving of the equations. Several of the kids need more than their fingers now and do better with a bag of counting blocks. I keep a box of counting blocks counted out into groups of 10 and stored in small sandwich bags for immediate use during any activity. I also make sure that every bag has 10 blocks of only one color. When I pass the bags out, I make sure each person at the table has a different color. This makes keeping track of supplies simple. The kids are required to count their cubes before return them to the bags and turning them in. It saves me time and energy when they are responsible for keeping track of supplies.
I give the kids as much time as possible to complete the activity (most get it done in the time allotted - I have high expectations for time use in the classroom).
Once the tables and floors are clean and supplies are put away, I have the kids gather on the floor and we discuss what we learned - what went well, and what was a challenge.
One thing that stands out is that as the numbers involved in the equations get larger, the challenge becomes more difficult and it takes more time to solve the equations then the activity before.
One student also noticed that more kids were using the blocks than the lesson before. You would be amazed at what young kids notice. Do not underestimate them.
The exit ticket is the finished product of the activity. As I collect them I look for any red flags that would indicate a student is not understanding subtraction. Two students stand out. One appears to have randomly glued the equations in the columns and one was adding the two numbers rather than subtracting. I ask myself how I missed those two as I was roaming!
The two kids are pulled into a small group the next day and I reteach the concept of subtraction to them. I have them use the counting cubes. I focus on the sign and have them tell me with each equation what the sign is called and what it means. Then I have them show me and each other how to solve each problem.