Sink or Float: Predict + Test + Talk

Level 1 focuses on concrete, hands-on learning.

Objectives

Materials

Instructions

Materials

A large clear tub or container filled with water

A variety of child-safe objects from home, such as a small toy car, a wooden block, a plastic spoon, a sock, a crayon, a small ball, a leaf, and a small, empty plastic bottle

Towels for spills

Smocks

Chart paper or whiteboard

Markers

Learning Objectives

Children will be able to make predictions about whether an object will sink or float.

Children will demonstrate observation skills by watching objects in water.

Children will be able to articulate their observations and predictions, using simple descriptive language.

Children will begin to understand the concept of sinking and floating.

Step-by-Step Instructions

1. Gather the children around the water tub and explain that today they will be scientists, like how a grownup might be a scientist at their job! Show them the collection of objects, reminding them these might be familiar things from their own homes.

2. Hold up one object, for example, the toy car. Ask the children, "What do you think will happen when we put this in the water? Will it sink to the bottom, or will it float on top like a boat? Talk with your family members at home about what you think!"

3. Record their predictions on the chart paper. You can draw simple smiley faces for float and frowny faces for sink, or write their words.

4. Have a child gently place the object into the water.

5. Observe together as the object sinks or floats. Discuss what they see. "Look! The car sank. It went all the way to the bottom. What did you predict?"

6. Repeat steps 2-5 with each of the remaining objects, encouraging discussion and predictions each time. If a child is hesitant, ask them to describe the object, "What colour is the leaf? Is it hard or soft?"

7. As you finish, ask questions like, "Were you surprised by any of the things that happened? Which things floated like a little boat your family might take out on vacation?"

8. Clean up any spills with the towels, just like we help tidy up our home after playing.

Educator Tip

Encourage children to talk to their families about this activity. You can send home a note saying, "Tonight, have a ‘Sink or Float’ chat at dinner! Talk about everyday objects in your home. What do you think will sink or float in the bathtub?" This strengthens the home-school connection and reinforces learning. Ensure the water level is safe for the age group and that children do not put objects in their mouths.

Assessment

Observe the children’s participation in predictions and discussions. Note their ability to use descriptive words when talking about the objects and their behaviour in water. For instance, are they saying "it sank" or "it floated" and are they able to offer simple reasons ("it's heavy," "it's light") based on their observations? You can also collect the chart paper with their predictions and observations as a record of their engagement.

Educator tip

Model language (sink/float/predict); ensure safe setup.

Assessment

Observe and note: ability to follow two-step instructions, use of new vocabulary in context, early problem-solving strategies, and sustained shared thinking episodes. Assess against Development Matters age-band expectations. Teacher checklist: engagement, prediction attempts.

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