18 Halloween STEM Activities With Free Printables That Use Kitchen Things

These halloween stem activities for kids run on baking soda, vinegar, straws, string and paper, which means the supply run costs almost nothing.

Every experiment pairs with a printable recording sheet so the afternoon counts as real science, whether you are running a classroom party or a backyard one.

The list splits neatly into ten printable sheets and eight no-print activities, all Halloween-themed, all genuinely messy enough to hold a child’s attention.

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1. The Experiment Recording Sheet

This sheet is the backbone of the whole session. Each child gets one at the start and carries it through every activity, writing a hypothesis before each experiment and a one-sentence conclusion after.

That before-and-after structure is what turns a fun mess into observable evidence, which is the point a teacher or parent needs to make to anyone who asks why the kitchen looks like this.

Print one per child on plain paper, no cardstock needed. It takes about two minutes to fill in the header and then the child keeps adding to it as the session moves forward. Set a rule: no starting the next activity until the conclusion line for the current one is filled in.

The most common mistake is handing it out too late, once the fizzing has already happened. Hand it out first, before any materials appear, so the hypothesis feels like a real prediction rather than a retcon. A quiet five-minute writing window at the start settles the group before the chaos begins.

2. Fizzing Pumpkin With Vinegar and Baking Soda

Each child scoops two tablespoons of baking soda into a small carved or drawn pumpkin shape made from orange card stock, then drips white vinegar from a pipette or spoon.

The carbon dioxide reaction makes the pumpkin ‘spit’, which is exactly dramatic enough for a Halloween setting. The science question on the table is simple: what happens when an acid meets a base, and how can we make the reaction bigger or smaller?

No printing needed for this one. You need baking soda, white vinegar, a pipette or teaspoon per child, a shallow tray to catch the overflow, and orange card stock cut into pumpkin shapes as the vessel holder. Groups of four to six work well. Allow ten minutes including cleanup.

The overflow catches children off guard and they pull back, which means vinegar lands everywhere. Put trays inside a larger bin liner before starting.

If the reaction feels weak, add a drop of dish soap to the baking soda first: it makes the foam tower dramatically higher and holds the bubble structure longer, which gives children more time to observe it.

3. Predict and Check, Sink or Float

Children predict whether each of six Halloween-themed objects (a candy corn, a small plastic spider, a cork bat cut-out, a rubber eyeball, a pumpkin seed and a piece of foil shaped like a ghost) will sink or float, then test each one in a clear tub of water.

The prediction column is filled in before touching the water. The result column is filled in after. The sheet makes the cognitive gap between prediction and result visible, which is the actual learning.

Print one per child. You need a clear plastic tub of water, the six objects listed above (or substitutes of similar variety), and a towel per table. The test takes about eight minutes.

The sheet includes a simple answer key at the bottom because the results are physically determined, cork floats and a full piece of foil sinks once folded dense enough, so correct answers exist.

Children almost always predict the rubber eyeball will sink because it looks heavy. It floats. That surprise is worth pausing on: ask why before moving to the next object, because the explanation (density, not weight) is the core concept.

If you have a postal scale, weigh each object and record it in the margin before testing: that one extra step moves the activity from observation into measurement.

4. Count and Graph the Results

After the sink-or-float test, children count how many objects sank and how many floated across the whole group, then plot the totals on a simple bar graph. This sheet adds a data-handling step to the physical experiment: the class result may differ from any one child’s table if objects were tested differently, and that discrepancy is worth discussing.

Print one per child, or use one shared copy projected on a screen. The graph has two bars pre-labelled ‘Sank’ and ‘Floated’, with a vertical axis numbered zero to ten. Children shade in the correct height and write the total above each bar. Allow five minutes. No extra materials needed beyond the results from the previous activity.

If every group got the same results the graph will look identical across the room, which is actually good evidence. If results vary, find the table where someone tested the foil ghost flat rather than crumpled: flat foil floats, crumpled foil sinks.

That variable is a natural launch into ‘what did we change?’ and introduces the idea of a controlled experiment without using that phrase.

5. Building a Spider Web From String Across a Doorway

Teams of two or three stretch white string or yarn back and forth across a door frame, taping anchor points to the frame with painter’s tape, until they have a web with at least eight crossing points.

The engineering challenge: the web must hold a small stuffed animal or crumpled paper ball placed at the centre without collapsing. Crossing point count and held weight are both recorded on the Experiment Recording Sheet.

No printing needed for this activity. Each team needs one ball of white yarn, a roll of painter’s tape, scissors and a lightweight object to test. Allow fifteen minutes to build and five to test. One door frame per team is ideal; a chair back works if space is tight.

The web almost always sags in the middle once weight is added, because children pull strands horizontally instead of at angles. The fix, once they discover it themselves, is adding diagonal braces. Resist telling them: give the team two extra minutes to problem-solve first. A failed first attempt is the best teaching moment in the whole session.

6. The Pumpkin Measuring Sheet

Children wrap a piece of string around a real small pumpkin at its widest point, mark where the string meets, then measure that length against a ruler to find the circumference.

They repeat the measurement at three points: around the middle, from top to bottom, and across the flat base. All three measurements go on the sheet, and children circle which is longest.

Print one per child. You need one small pumpkin per pair or group, a ball of string, scissors and a ruler. The activity takes about ten minutes. The sheet has three labelled measurement rows plus a question at the bottom: ‘Were all three measurements the same? Why do you think that is?’

Children often stretch the string too tight and get a reading that is too small. Model the technique once: the string should sit snug but not indent the skin.

If only one pumpkin is available for the whole group, children take turns measuring and compare their results, which adds a built-in discussion about measurement accuracy and why different people might get slightly different numbers.

7. Floating and Sinking the Sweets

Each child drops one of five Halloween sweets (a gummy worm, a candy corn, a piece of liquorice, a foil-wrapped chocolate and a marshmallow ghost) into a tall glass of water and watches what happens.

The twist: they then drop the same five items into a glass of fizzy water and compare. The carbonation changes the behaviour of several items, which makes for a genuinely surprising second round.

No printing needed here, though children can record their observations on the Experiment Recording Sheet they already have. Each child or pair needs two tall glasses, still water, fizzy water and five sweets from the list. Allow ten minutes. This pairs naturally with the Predict and Check sheet if you want to add a written prediction layer.

The gummy worm in fizzy water will eventually rise as bubbles attach to its surface, then sink again as the bubbles pop. That up-and-down motion holds children’s attention longer than a simple sink or float. Have them watch for a full two minutes before drawing conclusions, because the first thirty seconds look like nothing is happening.

8. Build a Paper Bridge, Plan First

Children design a bridge using only five sheets of paper and a strip of tape, strong enough to hold a small plastic pumpkin placed in the centre.

The planning sheet comes first: children sketch their bridge design, label the parts, and predict how many grams they think it will hold. Then they build from the sketch, not the other way around.

Planning before building is the engineering design habit the sheet is specifically training.

Print one per child. The build itself needs five sheets of standard paper, one strip of tape roughly 30cm long, and a small weight for testing (a small pumpkin, a stack of coins, or a 100g bag of rice works fine).

Allow twenty minutes: ten for planning, ten for building and testing. The sheet has a large blank design box, prediction line and result line.

Almost every first attempt uses the paper flat, which buckles immediately. The insight children need to find: folding the paper into an accordion or a tube makes it dramatically stronger. Do not hint at this. If a bridge collapses, ask ‘what would make it stiffer?’ and give them two more sheets to iterate. Iteration is the point.

9. Making Slime and Timing How It Stretches

Each child mixes a basic slime from PVA glue, water and a small amount of bicarbonate solution (baking soda dissolved in water works as a simple activator alongside a saline contact lens solution), adds orange food colouring and a sprinkle of black glitter, and ends up with Halloween slime.

The science step: they stretch it slowly and time how long it takes to snap, then pull it fast and compare.

Slime is a non-Newtonian fluid: it behaves differently under slow force and fast force, and that is the observation worth capturing on the Experiment Recording Sheet.

No printing needed beyond the shared recording sheet already in hand. Each child needs 60ml PVA glue, 30ml water, a quarter teaspoon baking soda, a teaspoon of saline solution, orange food colouring and a cup for mixing. Allow twenty minutes. This is the messiest activity: cover the table with bin liners first.

Slime that is too stringy got too much saline: add a drop more glue. Slime that will not come together got too little: add saline one drop at a time. The most useful thing a helper can do is circulate and adjust rather than giving everyone identical quantities, because the variables in the recipe become part of the learning.

10. The Slime Recipe Card

This is a take-home recipe card sized to print four-up on one sheet, trimmed into quarters. Each child gets one to keep, so they can repeat the experiment at home. The card lists every ingredient with the exact child-safe quantities and the four steps in order, plus a small ‘what is happening?’ box that explains non-Newtonian fluids in one sentence.

Print four-up on one sheet of standard paper, cut into quarters. One sheet of paper serves four children. No laminating needed, though a folded card slipped into a small zip bag makes a tidier take-home. Allow two minutes to hand these out at the end of the slime activity.

The ‘what is happening?’ sentence is the detail that makes the card feel like science rather than a craft project. Keep it on: when a parent sees it, it clarifies that the afternoon had educational intent. That framing matters for classroom parties especially.

11. The Straw Rocket Ghost

Children roll a small piece of paper around a pencil to make a tube, tape the end shut, draw a ghost face on it, and slide it onto a straw. A sharp puff of breath launches the ghost rocket across the table.

The science: lung pressure propels the tube, and the closed end creates the air resistance that keeps it flying straight. Children test three puff strengths (gentle, medium, hard) and measure how far the ghost travels each time with a tape measure.

No printing needed, though measurements can go on the shared Experiment Recording Sheet. Each child needs one straw, a small square of paper, tape, a pencil to roll around and a black marker for the ghost face. A tape measure or metre stick per group covers the distance recording. Allow ten minutes.

Rockets that spin rather than fly straight have a tube that is not quite sealed at the end, or a tube that is too loose on the straw. A tight roll and a solid tape seal fix both.

Let children who have a working design help fix their neighbours’ versions: peer troubleshooting is faster than adult intervention and keeps the energy up.

12. Tally the Bats, Then Order Them

A set of six bat silhouettes in different sizes sits on the sheet. Children count the wing-span tick marks beside each bat, write the total in the box, then number the bats from smallest to largest in the ordering column.

The activity combines counting, tallying and ordering: three maths skills in one Halloween-themed sheet. The answer key at the bottom makes self-checking fast.

Print one per child. No extra materials needed. Allow five to eight minutes. Works well as a settling activity at the start of a session or a calm-down between two messier experiments. Younger children (ages five to six) benefit from adult confirmation before they check the key; older children can self-check independently.

If the group finishes quickly, add an extension question verbally: ‘what is the difference in wingspan between the biggest bat and the smallest one?’ That one oral question takes the sheet from ordering into subtraction without any extra printing. Write the extension question on the board so early finishers have something to work on while the group catches up.

13. Growing Crystals in a Jar

Children dissolve as much table salt as possible into hot water (an adult pours, a child stirs) in a clean jar, add a drop of orange or purple food colouring, hang a piece of string tied to a pencil across the top so the string dangles in the liquid, and leave the jar somewhere undisturbed.

Crystals grow on the string over twenty-four to forty-eight hours as the water evaporates and the salt precipitates out. The science: supersaturation and crystallisation.

No printing needed for setup day. The observation happens the next day, which means this activity works best in a classroom setting where the jar stays overnight, or at a home party where children come back to check the next morning.

Each jar needs table salt, hot water, food colouring, a piece of string and a pencil. An adult handles the hot water. Allow ten minutes of active setup time.

Jars placed near a heat source evaporate faster and grow crystals sooner, but the crystals are smaller. Jars left cool and undisturbed grow larger, more distinct crystals over a longer time. If you want results to show the same day, use a very shallow dish instead: the surface area to volume ratio speeds evaporation noticeably.

14. The Shadow Length Chart

Children cut out a small paper Halloween figure (ghost, witch, cat: the sheet has three to choose from), stand it in a ball of clay or plasticine, and shine a torch at different angles to cast shadows.

They measure the shadow length at three torch positions: close, medium and far, then record all three on the chart and circle the longest. The concept: light source distance and angle both affect shadow length.

Print one per child. Each child also needs a torch (a phone torch works fine), a small ball of clay or plasticine to stand the figure upright, a ruler and a dark surface or sheet of dark paper for the shadow to fall on clearly. Allow fifteen minutes. Works best with curtains drawn or lights dimmed.

The figures fall over constantly because children do not press the clay base down firmly enough. A heavier base, a thicker piece of clay pressed flat on the table, solves it. If clay is not available, fold a strip of card into a triangular stand and tape the figure to it: just as stable and takes thirty seconds to make.

15. The Balloon and Static Ghost

Each child blows up a white balloon, draws a ghost face on it with a black marker, then rubs it vigorously on their hair or a wool jumper for ten seconds.

When they hold it near small pieces of torn tissue paper on the table, the tissue scraps leap up and stick. The science: static electricity, the balloon gains a negative charge and attracts the neutral paper scraps.

Children then test which surfaces generate more static: hair, wool, polyester and cotton.

No printing needed. Each child needs one white balloon, a black marker, a sheet of tissue paper torn into small pieces and a wool item to rub on. Allow ten minutes. This works as a mid-session energiser because children are moving and laughing throughout.

Humid days reduce the static effect significantly because moisture in the air dissipates the charge.

If the experiment falls flat on a wet day, move inside near an air conditioner or heater, or use a wool jumper instead of hair: wool generates charge more reliably in humidity.

Balloons also lose charge quickly, so the rub-and-test needs to happen within five seconds of rubbing.

16. Draw the Circuit You Built, Blank Frame Sheet

After building a simple circuit with a battery, two wires and an LED or small bulb, children draw what they built inside the blank frame on this sheet, label each component, and mark with an arrow where the electricity flows.

This is a post-activity diagram sheet: the circuit building happens first, then children produce the drawing as a scientific record. Drawing forces children to look carefully at what they actually connected, which often reveals misunderstandings about direction and continuity.

Print one per child. Each child also needs a 9V battery, two short lengths of wire with stripped ends (or crocodile clip leads), and one LED. Adult supervision is needed for wire stripping. Crocodile clip leads eliminate that step entirely and cost almost nothing from a science supplier. Allow twenty minutes total: ten to build, ten to draw.

Children almost always draw the battery, wires and bulb as separate floating objects rather than as a connected loop. Ask ‘can you trace a path from one end of the battery all the way back to the other end without lifting your pencil?’ That one prompt fixes the diagram immediately and reinforces the concept of a complete circuit.

17. Measuring Real Pumpkins With String

Children work in pairs with one real pumpkin, wrapping string around it at three points (top, middle, bottom), cutting a piece to match each circumference, then laying all three pieces flat on the table and ordering them from shortest to longest.

The maths step: they measure each piece with a ruler and record the three numbers. The physical comparison (laying the strings side by side) comes first, the measurement comes second, so children have a concrete intuition before the number confirms it.

No printing needed: measurements go onto the Pumpkin Measuring Sheet already printed. One pumpkin serves two to four children. You need string, scissors and a ruler per group. Allow ten minutes. This activity pairs directly with the Pumpkin Measuring Sheet earlier in the list and extends it from indirect measurement (wrapping) to direct measurement (ruler).

Children cut the strings too short by pulling them tight when wrapping. The fix is to mark the string with a marker at the meeting point instead of cutting while it is still on the pumpkin. That one change makes the measurement accurate.

If you have several different pumpkins available, groups can swap after measuring and compare results across pumpkin sizes: a simple data comparison that takes two extra minutes.

18. The Weight Prediction Card

Four identical prediction cards print on one sheet.

Each card lists five Halloween objects (a candy corn, a mini pumpkin, a plastic spider, a marshmallow and a small apple) and asks the child to write their predicted weight in grams next to each item, then weigh the real objects on a kitchen scale and write the actual weight beside the prediction.

The comparison between prediction and reality is the learning: most children massively underestimate the apple and overestimate the pumpkin.

Print one sheet per four children, then trim into individual cards. Each card needs a kitchen or postal scale, and the five objects listed. Allow ten minutes to predict, weigh and compare. Works well as a station that a small group rotates through while others do a different activity.

Children who have never used a kitchen scale need thirty seconds of instruction: show them where to press zero (tare), place the object, read the number. That setup time is worth it because weighing is a genuinely transferable kitchen skill. If only one scale is available, one child weighs while the other records, and they swap halfway.

Frequently Asked Questions

What age are these halloween stem activities for kids best suited to?

Most activities suit ages five to ten with minor adjustments. The tally and graph sheets work for ages five and up; the circuit and bridge challenges are better from age seven. Younger children pair better with an older partner for the measuring and weighing activities.

Do I need to buy special supplies or does everything come from the kitchen?

Vinegar, baking soda, salt, food colouring, straws and paper cover the majority of activities. The circuit activity needs a 9V battery and crocodile clip leads, which are the only items that require a quick online order. Everything else is a kitchen or recycling bin staple.

How do I make these work in a classroom with thirty children?

Set up four or five stations around the room, each with a different activity, and rotate groups of six every fifteen to twenty minutes.

Print one Experiment Recording Sheet per child at the start and use it as the through-line: every station adds one entry to the same sheet. That keeps the paperwork manageable and gives each child a single piece of work to take home.

Can I use these halloween stem activities for kids at a home party?

Absolutely. The fizzing pumpkin, straw rocket and balloon ghost are the strongest choices for a party setting because they are fast, dramatic and need no skill. The bridge and circuit activities suit a smaller group of four to eight where children can spread out and focus. Skip the crystal-growing for a party: the payoff takes a day.

Which activities are safest for the youngest children?

The straw rocket ghost, balloon static ghost, tally sheet and sink-or-float activities are the safest and simplest. All use materials with no heat, no sharp tools and no chemicals beyond food-grade vinegar and baking soda. Adults should handle any hot water for the crystal activity.

How long does the whole session take if I run every activity?

Running all eighteen back to back would take roughly three hours. A practical classroom session picks six to eight activities, mixes one messy active experiment with one printable sheet at each rotation, and fits comfortably into ninety minutes including distribution and cleanup time.