Early Math Counts

• The book, Who Sank the Boat by Pamela Allen
• A water table or bin large enough to fill with water and have several children gather around.
• Half-pint milk cartons for every child (washed thoroughly and dried)
• A balance scale
• Chart paper and markers
• Weighted objects such as pennies, rocks or heavy manipulatives that are small enough to fit into the milk carton boats

Note: Small parts pose a choking hazard and are not appropriate for children age five or under. Be sure to choose lesson materials that meet safety requirements.

1. Before beginning the activity, prepare the milk cartons. Staple the spout of each carton closed. Cut each carton in half vertically to make 2 boats.  Add a sail by taping a paper triangle to a craft stick and placing the stick in a ball of modeling clay in the center of the boat.
2. Explain to the children that today they are going to read the book, Who Sank the Boat, and try to figure out which animal sank the boat.
3. Make a list of things that are lighter than, the same as and heavier than. Divide the chart paper into the three categories and list the children’s answers under the appropriate categories.

1. Read the book, Who Sank the Boat. While reading the story, encourage the children to make predictions about the different animals and whether or not they will sink the boat.
2. After reading the book, demonstrate how the scale/balance is used. Use the weighed objects to determine which object is the heaviest, which object is the lightest and which objects weigh the same.
3. Give each child a boat. If you have time, you might allow them to decorate their boats to help distinguish the boats from one another.
4. At the water table, have the children place their boats in the water. If applicable, you might want to have the children arrange the boats in order from largest to smallest. Using the weighted objects, have the children try to sink their boats. Have them experiment with the objects. How many different objects does it take to sink the boats? How many of the same objects does it take to sink the boat? How many of the lightest objects does it take to sink the boat? How may of the heaviest objects does it take to sink the boat? Are the boats different? If it takes 10 pennies to sink a boat, does it also take 10 pennies to sink another child’s boat?
5. Have the children record their results.

Additional Extensions

• Blindfold a child (if a child is willing) and have the child take two different objects in his/her hands and compare the weight of the objects. Ask: Which object in heavier? Which object is lighter? Have the children check their answers on the scale.

• Experiment with objects on a boat. Challenge the children to sail the boat with four objects and then find out if the fifth object will sink the boat, just like in the story.

• Heavier: Having greater weight (e.g.,”Which object is heavier?”)
• Lighter: Having less weight (e.g.,”Of the two objects, which is lighter?”)
• Heaviest: Having the greatest weight (e.g., “Which object is the heaviest?”)
• Lightest: Having the least amount of weight (e.g.,”Which object is the lightest?”)
• The same: Identical in kind or quantity (e.g.,”Both objects weigh the same.”)
• Weigh: To measure according to weight (e.g.,”What object weighs more?”)

Early Math Glossary

Adapt Lesson for Toddlers

Toddlers may:

• Understand the correlation between various weighted objects and the sinking of the boat

Child care providers may:

• Have the children use only one type of weighted object. Ask: “How many pennies does it take to sink your boat?”

Adapt Lesson for Preschoolers

Preschoolers may:

• Understand the correlation between various weighted objects and the sinking of the boat

Child care providers may:

• Blindfold a child (if a child is willing) and have the child take two different objects in his/her hands and compare the weight of the objects. Ask: Which object in heavier? Which object is lighter? Have the children check their answers on the scale.
• Experiment with objects on a boat. Challenge the children to sail the boat with four objects and then find out if the fifth object will sink the boat, just like in the story.