⚖️ Equation Balance
Skill goal: understand that an equation is a balanced scale — whatever you do to one side, you must do to the other.
Observe
The scale below shows 2x + 3 = 11. Both pans hold exactly the same value, so the beam is level. What happens the moment you touch only one side?
Manipulate
Step log
Predict
Before you change it, what do you think will happen? If you add +1 to only the left side, which way will the scale tip? What if you then add +1 to the right side too?
See
Explain
Why it works: the equals sign means the two sides have exactly the same value — like a level scale. Adding or removing blocks from only one side tips it, but doing the same operation on both sides keeps it level. When a single x-block stands alone on one side, you can read the solution straight off the other pan.
Challenge
Solve the equation on the scale (isolate x), then type the value of x and press Check.