Tuesday, February 19, 2013

One Fish Two Fish Estimation Center

Hi friends!

You may remember that I showed you a couple of days ago how my Scholastic Book Fair is going Seuss-y. My library centers are also related to either Seuss or the book fair.

Today I assembled our One Fish Two Fish Estimation Center. You can click on that link and get the free download from my Teachers Pay Teachers store.

Here's how I put this estimation center together. I started with a goldfish bowl from Walmart.

I lined the glass bowl with a plastic bag before I put the colorful goldfish in because I don't want my students to breathe all over the helpless little crackers.

I tied the bag with a red ribbon.

I printed the instruction sign and entry forms and set them out at the center with pencils. It looked like this.

When students came to the library, the estimation center looked like this.

They were excited at the possibility of winning all the goldfish! But I felt like the center was more of a guessing game than a math center. I wanted to connect this library center to their classroom learning.

I asked a second grade teacher how she taught estimation, and then I made some upgrades to the center.

I added hundred charts all around the edge of the table. I found a free printable hundred chart online here and I made copies. This second grade teacher told me that in class, they think about putting one object on each square of the hundred chart. Will they fill the whole hundred chart? Will they fill more than one hundred chart? How many?

I also added this to the center.

I had an empty Petri dish, and I put 10 goldfish in there. Now the students can use this visual image to estimate how many groups of 10 might be in the bowl. (I didn't want to put the 10 goldfish in a baggie because I thought they might get smushed into crumbs.)

Now there are a couple of different mathematical ways to try to make an estimate, by tens or by hundreds. As for the correct total, I have to say that I did NOT actually count every single little goldfish. There are over 1000 in there! I used the serving size and amount on the nutrition label, and I multiplied those. So far, no one is even close. They are all estimating way too low.

I like the opportunity to bring math into the library, and the goldfish are a colorful addition to our decorations. If  you'd like to try this in your library, you can download the printables for free!


  1. I love that you went that extra step to make it a math center! Can't wait to set it up in our library!!! I had an "estimation station" using our bulletin board. Made a snowman out of styrofoam cups and had the kids guess how many I used. Nobody was even close - not even our principal!!

    1. Hi Shelly! It's a challenge to find math activities that "fit" in the library and can be meaningfully accomplished in a short time frame. I like your snowman idea. Any photos?

  2. Thanks for the great idea! I have Dr. Seuss themed centers in the library this week and the "Red Fish Blue Fish Estimation Center" is a hit with all grades K-8. I placed a flexible ruler at the station and it has been a hoot watching the kids use it to figure out their estimations. Next year I am going to put a space on the entry form for the kids to explain their thinking process.