Harder, Softer, This Way, That Way
A 45-minute Kindergarten lesson on testing how the strength and the direction of a push change how something moves.
Harder, Softer, This Way, That Way is a free 45-minute Kindergarten science lesson plan for Common Core standard K-PS2-1 — test how hard and which way you push or pull, and watch what the motion does. It is timed across 5 sections, gives the exact wording to use where the wording carries the mathematics, names 3 misconceptions with the teaching move that addresses each, and ends with an exit ticket and a printable worksheet with its answer key.
- Grade:
- Kindergarten
- Length:
- 45 minutes
- Standard:
- K-PS2-1
Kindergarten · Physical Science
K-PS2-1
Plan and conduct an investigation to compare the effects of different strengths or different directions of pushes and pulls on the motion of an object.
Objective
Students will be able to change one thing about a push and say what it did to the motion.
Students are successful when they can
- Changes only the strength of the push, and says what happened.
- Changes only the direction, and says what happened.
- Uses the words harder, softer, towards and away.
What you need
- One ball per pair, a marked start line, floor space
- Chalk or tape to mark where the ball stopped
- The printable practice sheet linked at the end of this plan
The lesson
Warm-up — guess before you push
5 min- Roll a ball gently across the front. Ask the class to guess where a harder push would stop.
- Mark both guesses on the floor before testing anything.
Teach — change one thing
12 min- Push the ball softly from the line. Mark where it stops.
- Push it hard from the same line, the same way. Mark that too.
- Say what was kept the same: same ball, same line, same floor.
- Say what was changed: only how hard.
- Now change direction instead: push the ball to the left, then to the right.
- Name the rule the class has just made: a harder push sends it further, and the push decides which way it goes.
“We changed one thing. What did it do to the ball?”
Investigate — three pushes each
15 min- Pairs take a ball to a start line and give it a soft, a medium and a hard push.
- They mark where the ball stopped each time with chalk or tape.
- They count the steps to each mark and say which push sent it furthest.
- Circulate and ask each pair what they kept the same.
Independent practice
10 min- Students complete the 'Harder, Softer, This Way, That Way' page.
- Read each question aloud once before they answer.
Close
3 min- Ask one pair to show their three marks and say what they changed.
What goes wrong, and why
Each of these is a reasoning error rather than carelessness. The fix addresses the reasoning.
Changes the push and the ball at the same time.
Why: Both are interesting, so both get changed.
Fix: Ask which one made the difference. If two things changed, nobody can say.
Says a hard push makes the ball 'better'.
Why: Bigger effects feel like better ones.
Fix: Ask what actually changed: it went further. Further is the observation.
Thinks a push only works one way.
Why: Every classroom push has been forwards.
Fix: Push the ball back towards yourself. The direction of the push is what it follows.
If they are not there yet
- Two pushes rather than three: soft and hard.
- Give the words harder and softer on a card to point at.
If they finish early
- Predict where a very hard push would stop, then test it.
- Find a push that makes the ball stop instead of start.
- Make the ball turn a corner using two pushes.
Exit ticket
Show me a soft push and a hard push with the same ball. Which one went further?
What to look for: The hard push named, with only the strength changed. A pupil who swaps balls between pushes needs the keep-it-the-same idea again.
Printable practice for K-PS2-1
Free to print and copy, answer key included. Each sheet can generate a fresh set of problems for a retake.
- Harder, Softer, This Way, That WayCircle the best answer.
Questions about Harder, Softer, This Way, That Way
How long does the Harder, Softer, This Way, That Way lesson take?
45 minutes, split across 5 timed sections: warm-up 5 min, teach 12 min, investigate 15 min, independent practice 10 min, close 3 min. The minutes are stated per section and add up to the stated length, so the plan can be cut or extended at a section boundary rather than abandoned halfway.
Which standard does Harder, Softer, This Way, That Way teach?
K-PS2-1 — K-PS2-1, Physical Science for Kindergarten: “Plan and conduct an investigation to compare the effects of different strengths or different directions of pushes and pulls on the motion of an object.” In plain terms, test how hard and which way you push or pull, and watch what the motion does.
What do I need to teach this lesson?
One ball per pair, a marked start line, floor space, chalk or tape to mark where the ball stopped and the printable practice sheet linked at the end of this plan. Everything listed is either ordinary classroom equipment or a free printable from this site — there is nothing to buy and nothing to prepare beyond photocopying.
What mistakes should I expect in this lesson?
Three, each a reasoning error rather than carelessness: changes the push and the ball at the same time; says a hard push makes the ball 'better' and thinks a push only works one way. The plan gives the thinking behind each one and the teaching move that addresses the thinking rather than the symptom.
How do I know whether the lesson worked?
The exit ticket asks: “Show me a soft push and a hard push with the same ball. Which one went further?.” The hard push named, with only the strength changed. A pupil who swaps balls between pushes needs the keep-it-the-same idea again. That tells you whether the class needs a reteach or a thirty-second conversation before you plan tomorrow.
Is there a worksheet to go with Harder, Softer, This Way, That Way?
Yes — 1 printable K-PS2-1 worksheet, linked at the end of the plan and free like the rest of the site. Each one comes with an answer key and 25 versions, so the practice after the lesson can be a different paper on every desk.
Is Harder, Softer, This Way, That Way free to use?
Yes. The plan, its printables and their answer keys are free to read, print and photocopy for your own class, with no account and no email capture. It was last reviewed on 8 September 2026. Please do not resell it or republish it as your own.
Last reviewed 2026-09-08. Aligned to K-PS2-1 of the Next Generation Science Standards.