Decomposing 2 & 3
Lesson 5 of 12
Objective: SWBAT show the different ways to "make" 2 and 3 with 2-colored counterl
“Girls and boys, is this 2?” I ask, showing 2 red counters on the big screen.
“Well, yeah, Ms. Novelli,” students respond.
“Hmm… is this 2?” I ask, showing 2 yellow counters on the big screen.
“Yes!’ they exclaim.
“But 2 red… 2 yellow… are they the same?” I ask.
“No!” students respond.
“But you told me they’re both 2!” I’m confused, I say, hoping my acting skills are paying off.
“Yellow can be 2 and red can be 2,” a student says matter-of-factly.
“But they’re not the same… and they are the same? How can different things be 2?” I press on.
“Well, as long as you have 2 of them, you can have 2 different things,” a student says.
“So there are different ways to make 2,” I say. “Let’s check them out!’
We begin with 2 red counters, and we color them in to record the combination on our recording page. We even total 2 red and 0 yellow. (The concept of 0 gets tricky sometimes… they always want to say there’s something!)
Next, we systematically flip over 1 red from the right side and we again color and write the numbers.
I have the students tell me to make the last red yellow, so that it’s all yellow, and we record our possibility.
Three is on the back, and for a moment, I totally forget my head. We do the first group of 3 together—just like we did for 2.
The students seem to be doing really well, and they ask to practice all by themselves, and I make a huge mistake and say, ‘Sure.”
Some kids start randomly flipping counters, and I see we have a mess. I try to swoop I and help a confused friend, but ultimately, I’m waiting for a chance to re-teach this!
Students show their different combinations to make 2 and 3. There are a lot of different combinations showing 2 red and 1 yellow or 2 yellows and 1 red. Hmm. We don’t quite have this concept “down,” I realize.