TRY THIS! Activities

Activity Name: Growing a creature ........and Shrinking a creature

Suggested Grade Level: K

Your name or school: John M. Tobin School


One of those growing sponge creatures ( we had a pumpkin ) Initially it measured about 2" by 3"
A bucket of water
Measuring tools
pan balance and/or other kinds of balances for weighing
graph paper 1" by 1" ruled
Sheets of large chart paper to record responses


Discuss what will happen when you place the miniature creature in the water.
Develop and model questions that stem from their prior knowledge with such sponges
(growing dinosaurs are perhaps the most popular)
Encourage predictions about size and weight

Place the creature in the water and wait.
We kept adding more water as needed periodically to be sure that the creature grew as much as it could.

Record observations at various intervals. Hourly, daily, after a weekend, whatever time spacing seems convenient
At each observation take the creature out of the water and pass it around.
Have children smell it and feel it
Record on chart paper children's responses.
integrate interactive writing practice
develop descriptive and expressive vocabulary
Make connections between various observations and responses.
Measure the height and width of the creature and record.
Trace the outline of the creature, if possible. (our pumpkin ended up being fairly flat so that tracing seemed logical and obvious.)
Repeatedly trace on the same paper so that you have a series of outlines that show the gradual growth of the outline tracing.
Weigh the creature using whatever balances you may have.
We recorded the weight of the creature in grams using a triple beam balance.
In the pan balance we measured the weight of the pumpkin against varied shapes of unit blocks.

Enjoy the learning and connections that occurs from making these daily observations

After a time when the children are convinced that the creature will grow no more ask what will happen when you remove the creature from the water.

Record their predictions

Remove the creature and wait.

Repeat the same observation and recording technique.

Put it back in the water again????


Sit back and relax and enjoy their excitement. This experiment had a life of its own. We loved touching and passing the creature. We learned how to look very carefully at something and try to find some small observation that someone else missed. We wondered about many things.

If it is not alive how does it grow?
How did it get dirty? How did the water get dirty? (Dirty hands while passing, of course. A great experience to refer to here when discussing the importance of washing hands)
Why did it twist when it dried?
How dry was dry? Would it get any drier?
We are currently observing the disintegration of the sponge as the material has been in and out of the water since October. Pieces have broken off, as well.


This was a very interactive and hands on experience for the children. The children have become very fond of the pumpkin by this time and every week we must include the "growing and shrinking" activity in our math workshops.


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