How many grapes equals a dozen peaches?

My 6-year-old cousin quipped to me that 100 grapes is equal to a dozen peaches. Deciding he was referring to volume, we came up with the following experiment which uses the displacement of water to equate volumes. Though simple (all materials in photo), this highly visual and surprising experiment has many important lessons and can easily be adjusted to be appropriate for any grade 1-12. 

Step 1

Fill a glass measuring cup with enough water to submerge a peach. If you do not have a measuring cup, you may simply use a big glass jar and a dry-erase marker to mark the water levels. Or, you may simply use two identical class jars side-by-side filled to the same level of water.

Have your students note the water level (300 ml in this photo).

Comments

[kelseymh]

Yay, Science! This is a wonderfully simple example of hypothesis testing. I especially like the way you've thought through the pedagogy to address a full order-of-magnitude range of educational levels.

I am going to pass this on to my daughter's preschool teachers (she's 3-1/2), as they've been doing a unit on measurements this term.

[samsmyth]

Awesome, I would be interested to see how this experiment fared with preschoolers.

[TANZMEISTER]

If you made a little boat you could have your students compare equality of displacement (weight) versus equality of volume.

[samsmyth]

That would be an excellent addition to follow-up with.

[CatTrampoline]

I really like the additional challenges and increasing complexities suggested for different age groups.

The low-cost, low-tech materials make it a good hands-on learning experience even during budget-crunch times. You get my vote.

[samsmyth]

Thanks!

[FlatLinerMEDIC]

Awesome