Can you really captivate your whole class with an ear of dried corn? Yes, if it's the Estimation Ear.

Hi All,

It's that time of year when dried corn makes an appearance in supermarkets and farm stands, in fall and Halloween displays, and even on front doors. You might want to bring an ear into your classroom and try an estimation event with it.

Have students sit in a circle, ideally with each person having a white board and marker. Pass the ear of corn around so everyone gets a good look at it. Have students describe what they see as far as structure, color, feel, etc. Use four senses (no taste!)

Ask students if they noticed how the ear is made up of separate kernels of corn. Then ask if they could estimate how many kernels there are on the whole ear. Give students an opportunity to think and write an answer.

Share the estimates, writing them down the estimates on the board and pointing out the range from lowest to highest. Now ask, is there anything about the ear of corn that they would want to know, that would help them make an even more accurate and confident estimate. For example, one thing that would be helpful would be to know how many kernels are in a row. Another thing would be to know how many rows there are.

Have a volunteer come up and count the number of kernels in a row. Have a second person count and verify it. With this new information, ask students if they would like to revise their estimates. (By the way, these numbers can vary greatly depending on the size of the ear you use and of course, the size of the kernels.) Write these new estimates on the board and show the range. Ask how this new bit of information impacted their estimates.

Now take a permanent marker and mark a dot on the first kernel in any row. Have someone come up and beginning with the dotted row, count all the rows as you turn the ear. Write this new information on the board. Ask students if they would like to revise their estimates again. Have students share their revisions and methods.

If you want to take this a step further you can actually remove the kernels from the cob, split them into groups and into cups, and then give these out to partners. Partners can do a physical count, put that number on the board and then invite the class to add up all of the numbers together to arrive at a final, accurate count.

Remind students throughout that estimates are "thinking guesses," not random, lucky guesses or exact counts. Estimates are also supported by what we can know or find out about an amount. Even partial knowledge can helps us make a better estimate. Participating in this activity helps reinforce these ideas.

All the best,

Bob

Comments

BAD Graphs

Hi All, Kids love to find other people's mistakes. (Not always that keen on finding their own of course.) Here's a chance for them to find some mistakes while learning some things about graphs. This activity focuses on learning about graphs and the parts of a graph that are important, but are sometimes neglected. When kids make their own graphs the most common omissions are: the title (what is this a graph of?), labeling the x and y axis (what do numbers and bars means?), and the units (how much of what?). A great way to remind kids of the importance of these elements is to have them try to deal with graphs that don't have them ie; BAD graphs. I give students a worksheet on which I have created four BAD graphs. They are BAD graphs because I leave off important elements like the title. Along with this students are also given a 4 item question sheet which they are to try to answer using the BAD graphs. I put the BAD graphs on the board or display. They look like this: I...

Piaget Would be Proud! Assessment, Mental Math, Manipulatives, Thinking, Missing Addends, and Kumquats!

Hi All, This is a super simple, but very revealing activity and so works as a good assessment. Fantastic for Pre-K, Kindergarten, and Grade 1. Try it out and see what you learn about your students. Display a small number of objects in your open hands. Here we have 4 kumquats. (Because I have a kumquat tree in my yard. Any small manipulative will do.) Put your hands behind your back. Close one hand and bring both hands back out in front of you to display 2 kumquats visible in one hand and a closed hand with the rest of them. Remind students that you started with 4 and there are still 4 all together. Ask students, what is in the closed hand. Ask how they know this. Then reveal and discuss. Try another one. Show the 4 objects again, 2 in each hand. Put your hands behind your back and redistribute with 1 object in one hand and 3 objects in the other. Bring your hands to the front and ask how many are in your closed hand. Ask how they know this. Then reveal and discuss. Yo...

EGG BOX SHAKE! IT'S WHATEVER YOU WANT IT TO BE.

Hi All, Shake it up! Egg Box Shake is noisy and fun! That's a big plus right there for most kids. Students like to create and keep their own math tools, and this is a great opportunity to do that as well. And, teachers can adapt the game to fit any level or mathematical operation. Win. Win. Win. Egg Box Shake originated as a coin identification and addition game for grades 1 – 3. I had students bring in an egg carton from home and then provided them with play money or coin stamps, ink pads, and card stock. They stamped out pictures of the coins onto card stock, front and back images, and then cut out the pictures. Students glued these pictures into the bottom of the twelve sections of the egg carton. Each player would get two beads, beans, chips, marbles, or any other small manipulative. They put these into the box and closed it. They then shook the box. When they stopped they opened it and saw where the beads had landed. Players added those two coins o...

MathStuff

Search This Blog