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Science Rocks!

Drops on Pennies


your results

Sent in by:
Amber of South Amherst, OH

The pennies are back with added change for an added challenge.

Materials Needed

  • different size coins like a penny, quarter, nickel, or dime
  • paper towels
  • water dropper
  • water in a cup
  • paper and a pen or pencil to keep track of your data



  1. How many drops of water can you fit on a penny? How about a quarter? Make a prediction. Start by putting one drop of water on a penny. Now, how many more do you think it can hold? Why?
  2. Keep adding drops to see how your prediction turns out. Remember to keep track of your data. Do it three times and then figure out the average number of drops that can fit on a penny.
  3. Next, try it with a quarter. Make a prediction.
  4. Use what you know about how many drops of water the penny held.
  5. Keep adding drops to see how your prediction turns out. Do it three times and then figure out the average number of drops that can fit on a quarter.
  6. Compare the number of drops the penny held to the quarter.

Now it's time for you to experiment. Think of a question that you want answered. Like, do all pennies hold the same amount of water? What other things besides size affect the number of drops each coin can hold? Write down what you thought was going to happen and what did happen. Then test out your question and send your reports in to our special feedback area. Every week, we'll publish a whole bunch.

Some of your Results

Ms.Luna'S Class, age 10 of Delano, CA wrote:
When our class completed the experiment, we got the following results: pennies 26, nickel 34, dime 28, quarter 33

Banana, age 10 of Deer Park, NY wrote:
I pot 50 drops on

Mr Disco of Deer Park, NY wrote:
first I put water then I put it on the penny and got 69 drops on it and thats what happened

Sam, age 13 of Deer Park, SC wrote:
when I did the science experiment I got 23 drops on the penny

Just, age 10 of NY wrote:
1# I put eyedroper in water 2# put eyedoper on penny 3# my anser is 13

Dharun, age 12 of Houston, TX wrote:
I tried 5 trials. In each trial the penny holds different amount of water droplets. The no of droplets in each trials are 18, 20, 21, 23, 19.

Mrs. H's 3rd Gr. Class of Easton, KS wrote:
The most drops we were able to put on a penny was 45. Our class average was 30 drops.

Mrs. B.'s 5th Grade of MO wrote:
We tried the experiment one. The penny held 28 drops of water. The quarter held 30 drops of water.

Ms. A.Z.'S 4th Grade Class of Miami, FL wrote:
Greetings scientists! Our 4th grade class performed this experiment in science teams and calculated the averaage amount of drops that fit onto a penny. The average for our class was 28 drops. That is a lot more than we expected. Fun experiment!

Demi, age 11 wrote:
I tried it with different liquids. I tried corn oil, corn syrup and lemon juice. The penny held the the most water.

Mrs. H's Class of Morristown, TN wrote:
The water stuck to the coins and formed a bubble. When we dropped more water on the surface it got bigger and bigger. Then, the bubble popped and water went everywhere on the plate!

Colleen, age 11 of Pennsville, NJ wrote:
When our class did the experiment, we were able to drop 144 drops of water on the quarter, 40 on the dime, and 97 on the penny.

Lauren, age 11 of Garden City, GA wrote:
the pennie had the second to the last # of drops the quater had the most the dime had the least it was fun and we squirted each other

Hailey & Jaiden of Poteet, TX wrote:
There was not much difference between the quarters and the pennies

Jasmine & Renata of Poteet, TX wrote:
The experiment was very cool. Thank you!

Nene, age 12 of New York City wrote:
well, when I did the penny experiment it was soi fun you can fit a lot of drops of water one little penny my experenice was great it was amazing I di dit with my class in science so it was great for me!!

Jassy, age 11 of Calgaray, AB wrote:
When I tried this I was able to put 44 drops of water on my Canadian penny before the surface tension was disrupted.

Danica, age 14 of Baxter, TN wrote:
penny:13, 12, 32, 33, 32 quarter:67, 41, 73, 60, 52 dime:31, 26, 18, 26, 12 nickel:47, 34, 59, 54, 31 Pretty cool!!!

Ashely, age 11 of Bronx, NY wrote:
I put the water in a penny and the number I got was??? 21 drops of water on the penny. it was so cool.

Mia, age 11 of CT wrote:
This experiment is so cool! I got 27 on the quarter and 15 on the penny.

Ella, age 10 wrote:
when the droper put on 3 drops it the water spills off of it.

Danielle, age 9 wrote:
i put 2 drops on the pennie and it overflew! It was a fun experment!

Lisa, age 11 of Shakopee, MN wrote:
for the pennies, there where different numbers and for the dimes, they where all the same number. for the nickles and quarters, the quarters where 299, and 298 and then the nickles where the most because they where 300, and in between 302.

Jackson, age 11 of Dallas, TX wrote:
I got 60 my first try then 126 then 160! For real!!

Luke, age 9 of Dallas, TX wrote:
I got 35 on my first try then I got 48

Veronica & Mary Kate of MB, SC wrote:
The penny had only an average of eleven, while the dime had anaverage of 18, the nickel had an average of 27, and the quarter had an average of 34.

Connie, age 11 of MB, SC wrote:
frist time it was 18 then it was 20 then 26

Haley, age 11 of Myrtle Beach, SC wrote:
26, 34. 3, 12, 19. 6

Joanne and Sarai, age 10 of MB, SC wrote:
17, 19, 31, 34

not yet implemented