1. Algebraic Strategies
Year 7

2. Guess & Check
Backtracking
Balance
Algebraic Strategies

3. 5n + 8 = 33 Try n = 4 (5 x 4) + 8 = 28 = 33 Now try n = 5 (5 x 5) + 8 = 33
Guess & check - example

4. Guess & check – try your own

5. Backtracking example 1 6s + 12 = 132 What is unknown? s
What is happening to s ? 6 x s
What is happening to 6 x s? (6 x s)+ 12
What is the result? 132
Backtracking example 1

6. Backtracking example 1 6s + 12 = 132 s x6 6 x s +12 (6 x s) + 12 20
120
132
- 12 6
result
We undo
multiply 6 by
dividing by 6
We undo
+ 12 by subtracting 12
Backtracking example 1

7. (3g – 40) 20 = 13 g x3 3 x g - 40 (3 x g) - 40 (3xg) – 40
100
300
260 13
Divide by 3
+40
X 20
result
We undo
divide 20 by multiplying 20
We undo multiply 3 by dividing by 3
We undo
subtract 40 by
adding 40
Backtracking example 2

8. Backtracking – try your own
4s – 9 = 51
Backtracking – try your own

9. j = j – 125 = 209 – 125 7j = 84 7j 7 = 84 7 j = 12
Balance – example

10. g = 189
Balance – try your own