Building equations
Strategy card
You can try combinations in a smart order.
- Step 1: Look at the target number.
- Step 2: Is it bigger or smaller than the numbers you have?
- Step 3: Bigger: try adding or multiplying. Smaller: try subtracting or dividing.
- Step 4: Check your answer by doing the math.
Tip: Estimate first: about how big should the answer be?
Worked example
Use every number and every sign once (× and ÷ before + and −). Which answer can you make?
Numbers and signs: 4 1 7 + ×
- A: 11 (the answer)
- B: 16
- C: 12
- D: 5
- E: 7
Why: 4 + 1 × 7 = 11. None of the other answers can be made with these numbers and signs.
Your turn
Your turn 1 of 3
Use every number and every sign once (× and ÷ before + and −). Which answer can you make?
Numbers and signs: 3 9 7 + −
Your turn 2 of 3
Use every number and every sign once (× and ÷ before + and −). Which answer can you make?
Numbers and signs: 1 4 7 + ×
Your turn 3 of 3
Use every number and every sign once (× and ÷ before + and −). Which answer can you make?
Numbers and signs: 1 8 8 + −
Keep practicing
Grown-ups: Make "target number" games with dice. Parent guide
Next lesson: Logic clues