Making 11 to 19
Lesson 9 of 11
Objective: SWBAT identify and build teen numbers by drawing a teen number and using base-ten blocks to build it.
Calendar time starts your math period off right! It builds an understanding of patterns, time, counting and ordinal counting. It is a great foundational tool.
For this lesson we do our daily calendar on Starfall which is free for the basic site. There is a fee for the extended site, but it is well worth it! See the calendar resource below to read the steps we take to complete calendar each day.
Today's counting review:
Count to 20 (builds number sense and counting fluency):
Countdown from 20 (counting down aids in kids learning the concept of subtraction and number sense that counting can go up or down the number line):
Count by 10's to 100 (beginning of a beautiful place value knowledge and helps the kids to see that one ten and extra ones make all the teen numbers):
After the Macarena count to 100, I think aloud about how the lady on the video got to 10 and said, "That is one ten." I say out loud, "I wonder why she said, 'That is one ten.' I bet it is because she had to count all the numbers between 1 and 10 to get to ten and (I hold up a ten frame) look, I have one 10 in my hand. Then she keeps counting one number at a time and makes the numbers 11-19 before she gets to 20, which is TWO tens."
I refer to the poster we made for teen numbers a few lessons back. It shows 10 + ___ = ___ for each number 11 to 19.
I then explain and demonstrate how I am going to build numbers 11-19 using base-ten blocks. I tell the kids that one ten-bar is equal to one ten-frame, it's just in a line instead of two sets of five.
I demonstrate pulling a card, reading the number out loud and building it using the base-ten blocks. I do it all under the doc cam. Before I had a doc cam, I used an overhead projector and base-ten transparencies and I've provided materials that you can use this way, as well as a replacement for the actual manipulatives.
I send the kids back to their seats one table at a time. They are expected to go to their seats SILENTLY as to not break the mathematical thinking we have elicited.
The helper of the day puts one tub (I put them together the day before) of materials on the center of each table. The table captain takes the materials out and places them on the center of the table.
They are now ready for guided instruction.
The guided instruction is crucial. The kids have built 11 to 19 using ten-frames and the transfer of knowledge usually pretty smooth, but the guided practice makes or brakes how smooth that transition is.
I start by having the kids sit at their tables with the manipulatives in the center along with a stack of face-down number cards 11 to 19. I assign each student at the table a letter, A-E (I have five kids at each rectangle table). I always chose the highest academic achiever for A because they catch on quickly and can model for others how the activity is done.
I guide them through five rounds of play. I pause and monitor for completeness between each direction.
First Player A goes:
1) draw the top card from the pile
2) read the number out loud to your table
3) use the base-ten blocks to build your number
I repeat these instruction with wait time for players B-E.
**This lesson can be taught with larger numbers in first grade so included number cards to 100 in the resource section.
Once everyone has had a chance to play a guided round of base-ten building, I let the kids work independently. While each student is building, the rest of the table is expected to monitor and assist when necessary. They are expected to assist respectfully and with kindness.
See video of students hard at work doing their base-ten building.
The kids build numbers 11-19 until time is up. I have them clean up their materials, and gather back on the floor for closure.
Once time is up and the supplies are put away, I have the kids gather back on the floor (count backwards from 5) to discuss what we learned and what we found as a challenge.
The kids explain how easy it was to do because they had already done the ten-frames and this was a lot like those.
One student asks why we didn't use the ten-frames this time and I explained that we won't always see numbers 11 to 19 in ten-frames. Sometimes they will be in addition problems, some times in ten-frames, and some times in base-ten blocks. It's good to be able to recognize 11 to 19 in all different ways.
One student says that it was harder to keep track with the base-ten blocks because the ten-frames are all on paper and the base-ten blocks are real and can "roll" away. I explain how that is a good example of why need to use our tools appropriately.
I ask a few kids to come up and show us how they modeled some of the numbers. I also had them explain to the class how and why the model they built represented the number I gave them. I did this because it is important for the kids to be able to explain and defend their thinking in mathematics. If they can explain it, then they truly know it.