1st Grade – 3 Act Math – Shark Bait

I have been borrowing a lot of 3 act tasks from Graham Fletchy‘s blog.  Today we did a measurement lesson he calls “Shark Bait.”  This was our first 3 Act lesson in 1st Grade at York and we used Nearpod to make this an interactive lesson using ipads.  Students worked in partners to discuss, generate questions, estimate and prove their solutions.  The thing we love about Nearpod is that it allows the class to stay together as we work through the activities and allows for interactivity by having students respond and even draw pictures of their solutions.

We presented this to students by telling them that this would be a new type of math lesson, that we would not be giving them their objective upfront, but that they would have to determine the math they used at the end of the activity.

Act 1: Video

What do you Wonder?  Examples of student responses:

“How big is it?”  “How tall is the worm?” “What is the length of the worm?” “How many inches is it?”

Oh so you are wondering about the size of the worm.  What do you think he used to measure the worm?

“Cubes”  “Squares” “Blocks”

Oh yeah, I saw that too, it looked like he was using blocks to measure it.  So we want to know about how many blocks it would take to make it to the end of the worm?


We then talked a little bit about estimation and an estimate that was too high and one that was too low.  Then students were asked what estimate did they think was just right?

2016-01-07 Branizor Shark Bait

2016-01-07 Tummons Shark Bait.png

Act 2: So then we asked how we could find out?  We allowed students to talk to each other and then told them they could use any of their math tools in their room that they thought would help.

Many students rushed up to the math materials and one group stayed behind.  I asked the little boy in the group if he had an answer.  He said, “yes, it’s 22.”  I said, wow can you explain how you got that answer?  He said, “yes, 5 + 5 is 10 and then 5 more is 15 then 20 and 2 more is 22.”  I then asked him and his partner if they could then work out if the worm grew 20 more cubes, how long it would be.  While they worked on that, I went to check on some other groups.

One little girl had a bunch of nickels out.  I asked her what she was doing and she had them arranged in an array with 4 in each row.  I said, hmmm let’s look at the information we have, how many of each cube does it say their are.  She said “five.” So could we arrange them in groups of 5? “yes.”  She said “it’s 22!”

Another partner group was getting out connecting cubes.  They had two towers of 10 and a tower of 2.  When I asked them about their tower they said it’s easier to add 10 so they just made two tens and a two and it was 22.  When we later shared out, I called them to the board and pointed to the information.  I said, you said you used two tens.  Where did those two tens come from?  They pointed to the top two fives and said that is ten and that is ten (pointing to the bottom two).  “and then we added two more.”

After everyone had a chance to draw their answers on the ipad (we had to talk about what it looks like to prove your answer with a drawing or number sentence), I called up a few students to share their strategies.

Act 3: I then asked, “do you want to find out if your solutions are correct?”


We played the act 3 video as they watched hopefully to find that they were all correct!  Lots of little thoughts of satisfaction floated around the room:)

The last thing I asked was, so I told you we were going to come back to our objective.  So what math did we do today?

“Adding.” “Counting.” “Measurement.” “Doubles.” “Skip counting.”

We had such a great time with these kiddos today!  I am always blown away by the level of deep thinking and conversation I hear with kids at each grade level.  Today was no different!