Learning About Tides for Kids

When visiting the beach, curious children may ask why the ocean rises so high at one point of the day and then drops so low at another. You can explain the nature of tides to children with a number of engaging activities. Whenever possible, look for hands-on demonstrations and explanations, always in keeping with the children's ages and learning levels.

Celestial Suspects

To teach children about the gravitational causes of tides, give them a few hints and then let the students work in small groups to solve the problem. For example, start the class by showing the students two pictures of the same beach or bay, one at high tide and another at low tide. Tell the class that they will have to work as detectives, in small groups, to determine the cause of the change in the water's height. Next, present the class with two more photographs, of the sun and the moon. Tell them that these photos are the prime suspects in their investigation. They have to figure out how either one, or both, are responsible.

Magnet Study

Use magnets, iron shavings and magnetized washers to demonstrate the magnetic effect on the earth's oceans. To give the presentation, have all the students gather around a central table. Show them a dish filled with iron shavings. Ask a student to dip the magnet close to the dish, coming very close to the shavings. Note how a few shavings will seemingly "leap" up to the magnet. Clean the magnet of shavings. Have another student hold the same magnet above a magnetized washer. Have the students note how close the magnet and washer must be for the attraction to pull them together. Integrate the lesson into the students' understanding of liquids and solids, helping them understand why the oceans bulge in attraction to the moon or sun, whereas the land masses remain relatively unmoved.

Spring and Neap Tides

After explaining the basic lunar influence on tides, provide students with a chart of tide levels over the course of the year. Have students work in groups to study the data and formulate hypotheses as to why there are more accentuated tides twice during the year. For older students, don't mention the sun's influence explicitly; let the groups arrive at the explanation either through inductive reasoning or through research.

Math Extension

For older kids, have your students create fictitious planets with different sizes and distances from the nearest moon and sun. Have the students hypothesize the effects of celestial bodies on the planet's tides. Award points based on the students' creative thinking and their coherent exposition of mathematical and logical processes, not on the specific values of their answers.