Recreating the past – Coffee grounds fossils (4th Grade)

Without fossils, we would know nothing about prehistoric life. Fossils are the remains of animals and plants that died a very long time ago and became preserved in rocks. These remains are our window on the past. They show us the amazing variety of life that thrived and then disappeared over millions of years of Earth’s history.

Fossils are preserved remains of once-living things, such as bones, teeth and claws. Usually the remains were buried in sediments – layers of tiny particles such as sand, silt or mud. Very slowly, the layers and the remains inside them turned into solid rock.



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We need:

  • 1 cup of used coffee grounds.
  • 1/2 cup of cold coffee.
  • 1 cup of flour.
  • 1/2 cup of salt.
  • Wax paper.
  • Mixing bowl.
  • Starfish, seashells, small dinosaurs, or other objects for the impressions.
  • Empty can or a butter knife.



  1. Stir together the coffee grounds, coffee, flour, and salt, until well mixed.


  1. Press the small objects firmly into the dough, to leave an imprint. Remove the object, and there’s your fossil! You can use a toothpick to poke a small hole near the edge of the coffee ground fossils, if you want to hang it later.


  1. Let the coffee ground fossils dry and harden overnight.


One of our fossils:






4th Grade – Natural Science: A visit to the laboratory (1st part)


Que mellor maneira de comezar as clases de Natural Science que iniciándonos na actividade científica no laboratorio da escola? A semana pasada as nenas e nenos de Alexandre Bóveda e Bertrand Russell (4º EP) fixemos unha pesquisa sobre os diferentes aparellos que podemos atopar nun laboratorio de química. Cando entendamos para que serve cada un deles poderemos facer algún experimento adaptado á nosa idade e ao noso plan de traballo. Moitas grazas ao profe Román pola súa colaboración!

Stalactite and Stalagmite Formation – 4th Grade

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Stalactites and stalagmites found in caves are an impressive feature of nature but they take a long time to form. Let’s speed up the process by making our own stalactites and stalagmites!

Stalactites grow very slowly and to observe their growth would take thousands of years. The purpose of this experiment is to observe how the stalactites grow, how fast they grow in 7 days, and what shape they will form into.

The hypothesis is that over the course of 7 days, the stalactite will grow to about 2 1/2 centimeters. It will also form into a downward tapering spiral shape

We did some experiments with warm water and others with cold water. Hugo, Laura, Manuel, Petra and Samuel think that the experiments with warm water will get better results. We’ll find out soon!

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