I keep a class-size number line from 1-120 in my classroom. It runs the full length of my counter on one wall. I have used it for many different math lessons and the kids refer to it at times. Today, I will have them help me mark the numbers that we say as we count by 10's. I will mark them with a sticky tab.
I want to review with them the terminology we have been using for our place value discussions. My main points I will discuss with my class are:
It is important for them to build a strong foundation now for correct math terminology and be able to use this vocabulary when discussing their ideas with their peers (MP6). They need to know the difference between the words and how to use them correctly. I will have my students take turns to come up and help me put examples on the chalkboard. Check out the pictures and videos in the resource section.
Common Core standard 1.NBT.B.2c is a first grade expectation that builds on set Kindergarten skills. Kindergarteners learns to compose numbers to 19 by combining a ten with ones. The first grade standard increases this knowledge by setting an expectation to build sets of tens and identify their amount, ex. 8 tens equals 80 (1.NBT.B.2c).
I will have my students continue to practice this skill by building a model to represent their tens. Constructing a model will force them to use their reasoning skills and plan ahead for the number they are attempting to represent (MP4) Look at the picture of a student finding sets of ten. Make sure to check for any circling sets of ten mistakes. You want to catch those and point them out to your students and have them fixed promptly.
Students, I am going to give you a large sheet of paper. Watch me build a model on the board to represent 20. (Write a 20 and draw 20 stars.) Count with me as I draw my stars. Now, I need you to help find my sets of ten and circle them as a group. (Point, count and circle the sets of ten.) Let's count by 10's to 120. 10, 20, 30... 120. Now these are our numbers we say when we count by tens. I want you to pick a number that is 40 or higher and illustrate it with any object you want to draw. Then go back and circle your sets of 10. Don't forget to write the number you illustrated on your paper.
I have 5 groups of 4 students in my room and will use these groups for our closing piece for this lesson.
Students, I want you to work with the members of your group to model for me some numbers I am getting ready to say aloud. You will be modeling using your fingers. How many fingers do each of us have? (10) Each time I call out a number you may only need some of your group members to show me fingers and you may need everyone to show me your fingers, so make sure to talk to each other and decide how your group is going to show me the answer.
Show me 30. (3 students will hold up their fingers up at each group.)
Show me 10. (1 student will hold their fingers up at each group.)
Continue with 20 and 40.