Numbers in the Teens
Lesson 3 of 10
Objective: SWBAT create base ten models to represent numbers 11-19.
Setting Up the Learning
This lesson transitions students from using ten frames to using base 10 models. This is aligned to MP5, use appropriate tools strategically. Students learn how to represent numbers using both tools. Students also focus in on the concept that 11-19 can be built with 1 ten and the appropriate number of extra ones, which builds directly from the Kinder standard (K.NBT.A1).
Yesterday we showed the numbers 11-19 using ten and some more. We used the ten frames to help us show these numbers. Today we are going to work on 11-19 again but we are going to see how we can show these numbers in base ten blocks.
We looked at the numbers 11-19 with stairsteps, ten frames and now we are going to show you the other way we can show these numbers. Understanding these numbers will help us use them in problems for the rest of first grade.
Objective : Your thinking job today is: What strategies can I use to help me represent numbers with base ten blocks?
*Lesson image copyright Harry Kindergarten.
I'll show 4 number cards of teen numbers (10, 12, 13, 17). What do all of these numbers have in common? (Push students to notice they all start with a 1)
Let’s choose one number-let’s do 13. I want to show 13 on a double ten frame like we did yesterday.
Partner Talk: What will 13 look like on the ten frames?
I'll highlight how a student said to make 13 and show it on a double ten frame.
- How many full ten frames do we have? How many extra people?
Restate: I see that we had 1 full ten frame and 3 extras. 1 and 3.
T+T: How could I show this with base ten blocks?
I'll quickly discuss that a base ten rod has 10 blocks in it. We call it a ten. I will count the blocks within the base 10 rod to prove that it has 10 cubes in it. This helps students understand the tools, which addresses CCSS Mathematical Practice 5, "Use appropriate tools strategically".
- I see I need 1 full ten stick so let me take that out first. Do I have 13 yet? How many do I have? How many more do I need to help me show 13? Do I need more tens? I need just extra cubes.
- How could I count these cubes to make sure I have 13?
- Let’s think about what the numbers in 13 mean. We made 13 with 1 ten and 3 extras. What did the 1 mean? What did the3 mean?
Present strategy share problem: Show how you could make 12 with base ten blocks. How did you know how to make the number?
Work Time: I'll use this time to float and ask questions to push students to a "higher" strategy (see below).
Possible strategies: (lowest to highest)
- Students take out 12 individual cubes and then build 1 ten and some extra
- Students take out 1 ten and count the cubes by ones (1, 2, 3….10), then they add 2 more as they count “11, 12”
- Students take out 1 ten and say “10” then the count on 2 more “”11, 12” and take out 2 more cubes
- Students look at the number 12 and then know 1 means ten and 2 means ones
I'll choose 2 strategies to show how students figured out how to make the number using tens and ones. I'll start with one of the lower strategies and then definitely include the structure of the number as a strategy
- How many cubes are in the ten stick? How many extra do they need?
- How did they know to use 1 ten stick? How did he/she know to use 2 extras?
- How could I count this to make sure I have 12?
- Let’s look back at the number 13. How are 12 and 13 the same? Why do they both have a 1 in the front? What is that 1 telling us?
- Make a prediction. If you were to make 15, how many base ten blocks would you need? Why would you need 1 ten?
For this activity, I printed copies of the free number cards from Phenomenal First Grade.
1. Student pulls a card.
2. Student builds that number with base ten blocks.
3. Students record how they did it in pictures and in words (as a way to incorporate the CCSS push for writing across the curriculum).
Group A: In need of intervention
Goals: Students may still need ten frame structure. Have students show on ten frames and then build the ten sticks.
Activity: Students use numbers 11-19 with ten frame and cube support (Write in choice numbers, make multiple problems)
Group B: Right on track
Goals: Students have a flexible use of strategies to show the number with base ten blocks and probably use the structure of the number as his/her primary strategy. May use another strategy to “check”
Activity: Students use numbers 11-19 without ten frame support
Group C: Extension
Goals: Students use the structure of the number to represent the tens and ones. Students get “push numbers” above 20 to see if they can generalize their understanding to larger number sets.
Activity: Students use numbers 15-29
See Numbers in the Teens Recording Sheet.docx for all independent practice!