Handout: The Equation Balancer
Keep the scales balanced by doing the same thing to both sides!
Example:
Solve for x:
x + 6 = 14
To get 'x' by itself, we do the opposite of '+ 6', which is '- 6'. We must do it to both sides.
x + 6 - 6 = 14 - 6
x = 8
Your Turn: Solve for the variable
-
a + 10 = 22
a = ___
-
b - 5 = 11
b = ___
-
3c = 18 (Remember, 3c means 3 × c)
c = ___
-
d / 4 = 5 (d divided by 4)
d = ___
Challenge Zone
Can you solve this two-step equation?
2x + 3 = 15
Hint: Get rid of the '+ 3' first!
x = ___
🔑 Kaiako answer key
Your Turn
- a + 10 = 22 → a = 12 (subtract 10 from both sides)
- b − 5 = 11 → b = 16 (add 5 to both sides)
- 3c = 18 → c = 6 (divide both sides by 3)
- d ÷ 4 = 5 → d = 20 (multiply both sides by 4)
Challenge Zone
- 2x + 3 = 15 → 2x = 12 → x = 6. Undo the + 3 first, then the × 2. Check: 2(6) + 3 = 15 ✓.
Watch for: insist on both sides being written at every step, not just the answer. The whole point of the balance image is that the working shows the balance being kept.
📋 Teacher Planning Snapshot
Ngā Whāinga Ako — Learning Intentions
A worksheet for Lesson 4, solving one-step equations by keeping both sides of the whārite balanced.
Ngā Paearu Angitū — Success Criteria
- ✅ I can keep an equation balanced by doing the same thing to both sides.
- ✅ I can solve a one-step equation and write both sides at every step.
- ✅ I can undo the constant first in a two-step equation.
Differentiation & Inclusion
Physical balance scales make the idea concrete and are worth the setup for ākonga who find the symbols abstract. Insist on both sides being written at every step — that habit is what makes Lesson 5 possible. The Challenge Zone is optional at this stage.