3rd Grade · Week 1 of 36 · Science
Forces: balanced and unbalanced
1. Hook
- Hear the goal. Watch one worked example (pictures + steps).
- Try the interactive lab on this page. Move something. Read what happened.
- Guided fills, then independent practice, then the scored quiz.
- Teach it back: one example + the usual mistake.
There is no classroom teacher. This page teaches you. The lab is on this site — not an outside classroom. Stay on this page. The pictures, the game, and Your work are the lesson.
Tug-of-war: when does the rope move, and when does it stay still?
Then: lab → guided → quiz → teach it back. The lab is the lesson, not a decoration.
2. Teach
Plan and conduct an investigation of balanced and unbalanced forces on an object's motion (NGSS 3-PS2-1).
Standards alignment: NGSS 3-PS (domain-level; works with any state’s standards)
STEM this week is Forces: balanced and unbalanced: look, write a fact, label a guess, then test one change.
- A force is a push or a pull. Forces have a strength and a direction.
- Balanced forces are equal and opposite; the object doesn't change its motion (stays still or keeps moving the same way).
- Unbalanced forces are unequal; the object speeds up, slows down, or changes direction toward the stronger force.
Gravity pulls things down; a table pushes up on a book, so the forces on the book are balanced.
Friction is a force that slows things down.
- Two teams pull with 50 and 50: balanced, rope still.
- Team A pulls 60, team B 50: unbalanced.
- Rope moves toward A.
- Difference: 10.
- Stronger side wins!
Push a toy car with one finger, then two; push from both sides equally. Record what happens.
Thinking a still object has no forces on it.
Bridges stay up because forces are balanced.
No classroom teacher today — this page is the lesson. A grown-up sits nearby. Model once, wait 10–20 seconds, then prompt. A grown-up sits nearby. Model once, wait, then let the child try.
See it · try it (interactive lab)
Do this lab on Life Academy. Move something. Read what changed — then quiz.
Play & explore
Hands-on practice for this lesson. Your progress saves automatically.
Your work — type it here
Do the lab (tap Look, Fact, Guess, Test). Then type what you saw, in kid words.
3. Guided practice
Try these with me — type the missing word, then check.
Reveal the thinking
Balanced = no change; unbalanced = change.
4. Independent practice
Work the set. Check when finished — this is practice (mastery quiz is next).
5. Mastery check
Scored quiz — results save to your gradebook.
The lab is on this page
Do the experiment here. Change one thing. Read what happened. We do not send you to an outside simulation site. Today: Forces: balanced and unbalanced.
Classroom · Gradebook · Transcripts
Stay on this page. The studio, the lab, pictures, and Your work are the lesson.
6. Reflection / teach-back
Teach-back: Explain Forces: balanced and unbalanced in your own words. Give one example and name the usual mistake.