Sink and float activities for toddlers: a 5-day plan

This five-day plan of sink and float activities for toddlers introduces children in Pre-Nursery (ages 2–3) to basic water science through hands-on investigation. Across five structured sessions, learners predict whether classroom items, fruits, balls, and natural objects stay afloat or submerge. They practise making comparisons, build foundational science vocabulary, and explore the colour blue through guided sorting, crafts, and sensory water play.

At a glance

Dimension	Details
Age band	Pre-Nursery (ages 2–3)
Length	5 days
Learning goals	Distinguish sinking from floating, test predictions with everyday items, observe fruit buoyancy, test covered balls, and explore the colour blue
Key materials	Water tubs, classroom items, sink and float labels, oranges, assorted balls, bubble wrap, plastic bottles, natural items, and blue craft supplies
Printables	Pre-Nursery Unit 2 Week 4 — Sink and Float (lesson plan) and the complete Sink and Float Week Package

The five-day plan

Day 1: Investigating Sink and Float phenomenon

Children gather around water tubs to explore how various classroom objects behave in water. Working in small groups, they examine pencils, blocks, and coins, predict which items will sink or float, and test each object. Learners observe whether items drop immediately or sink slowly, then sort them into baskets using float and sink labels alongside Making Float/Sink Representational Art. During literacy and numeracy time, children practise science vocabulary like observe, predict, float, and sink while answering riddles about blue items and pasting blue crepe paper onto a fish outline.

“Why do you think some things go under water and some stay afloat?”

Because small testing items such as coins present a choking hazard for children at this age, maintain active adult supervision throughout the water station.

Day 2: Discovering Fruits that Float

Day two centres on fruit buoyancy as children test whole oranges and orange rinds against peeled oranges in water containers. In small groups, learners discover that whole oranges and peels float on the surface, whereas peeled oranges sink directly to the bottom. For literacy and numeracy, children watch a puppet retelling of The Thirsty Crow, then watch an adult drop large stones into water to see how they raise the water level, before searching for blue objects in picture books alongside Making a Blue Colour Waterfall.

“Do you think the size of the object affects sinking and floating? Why or why not?”

Check family dietary records and food allergies before children handle fresh fruit in the classroom.

Day 3: Experimenting with Balls-Sink or Float

Children investigate a collection of assorted balls—including rubber, ping pong, tennis, and golf balls—in transparent water tubs. Learners hold each ball to predict whether it will sink or float, noting how heavy or light it feels before testing it. They then wrap sinking balls in bubble wrap and tape to discover how air-filled coverings can make an object float. In the literacy and numeracy segment, children practise prediction vocabulary before moulding blue playdough with large loose parts (too big to swallow, with an adult close by) and completing Making Rainfall using Straws.

“Do you think we can play with all these balls in the water? Why or why not?”

Day 4: Exploring Water Globes

Adults fill clear plastic bottles with water and small items like sequins, beads, buttons, and glitter, then glue the lids shut so the bottles cannot be opened. Children shake the sealed bottles, and watch how different objects drift downward, float, or settle at the bottom. They observe that lighter decorative pieces swirl slowly while heavier items drop rapidly. During literacy and numeracy time, children reinforce vocabulary like observe and compare, play a memory word-chain game of blue items, and paint paper-plate peacocks supported by Creating a Swimming Scene.

“Can you think of the reason why some things float and some sink?”

Day 5: Show & Tell and Rhymes recitation

The final session takes exploration outdoors as children dig stream channels on an inclined slope and pour water down the gradient. They release natural garden items like twigs, leaves, and large stones into the current, observing which materials float along the moving stream and which sink to the bottom. In the classroom, children present their discoveries during a Show and Tell reflection and prepare no-cook coconut ladoos using condensed milk and desiccated coconut, after checking allergies and dietary needs with families. For literacy and numeracy, children recite an action rhyme about flowing streams and assemble a collaborative blue collage on chart paper alongside Making Stamp Art using Fork.

“Through your exploration, have you found any new ideas on why things float or sink?”

Adapting the week

These practical adjustments allow educators to tailor the five-day investigation to different group sizes, learning paces, and classroom settings:

• For younger or less confident children: Present only two contrasting objects at a time, such as a large wooden block and a plastic bottle cap. Pair each demonstration with consistent physical gestures, tapping the surface for “float” and pointing downward for “sink” before asking learners to sort items independently.
• For children who need more challenge: Introduce timed observations to compare sinking speeds. Ask learners to predict whether coins and golf balls, dropped in by an adult, sink at the same rate, or test how varying layers of bubble wrap affect an object’s position in the water.
• For a small space or no outdoor access: Replace outdoor digging with an inclined plastic tray, gutter section, or baking sheet positioned over a basin. Children can pour water down the slope to observe how floating leaves and sinking stones (larger than a child’s fist, with an adult close by) behave in moving water without leaving the room.
• For home learners: Carry out the tests during bath time or kitchen wash-up, staying beside the child the whole time, using household items like plastic cups, spoons, and orange rinds. Encourage children to describe what they see and document their daily findings through simple drawings.

Questions teachers ask

How do you explain sink and float to toddlers?

Focus on direct sensory observation rather than scientific explanations of density or buoyancy. At this age, children understand concepts best through physical contrast and repeated demonstrations. Explain that some objects stay on top of the water to float, while other objects fall down through the water to the bottom to sink. Reinforce the vocabulary consistently during water play by pairing the words with hand gestures and encouraging children to describe what they see.

Why does an orange peel make an orange float?

An orange peel contains thousands of microscopic air pockets that act like a built-in flotation jacket. These trapped pockets of air make the unpeeled orange buoyant enough to rest on the water’s surface. When you remove the peel, the fruit becomes heavier than the water it displaces and sinks straight to the bottom. Testing peeled and unpeeled oranges gives children a clear, memorable demonstration of how outer coverings change whether an object sinks or floats.

How can teachers manage indoor water play without excessive mess?

Establish simple physical boundaries before opening the water containers. Set shallow plastic trays or waterproof mats beneath tubs to catch inevitable drips, and fill containers only halfway so splashes remain contained. Keep groups small, limiting each station to two or three children with dedicated roles like testing objects or drying them with towels. Providing clear sorting baskets for wet items ensures classroom floors stay dry and orderly throughout the session.

Get the printables

All daily lesson plans, supply lists, and printable activity sheets for this theme are available in the Superbuddy library. You can download the complete Pre-Nursery Unit 2 Week 4 — Sink and Float (lesson plan) or access the full Sink and Float Week Package from the Superbuddy library, which is free to start. To discover complementary hands-on science activities and early years curriculum materials, explore our topic hub: water.