Squares next to a ten — Speed Calculation

The fast method

Step from a neighbour — “square the round number, then step up or down one”

1. Find the round neighbour and square it: 70² = 7 × 7 = 49, then two 0s → 4900.
2. Ends in 1 (one more)? Add the round number and the number: 4900 + 70 + 71.
3. Ends in 9 (one less)? Take them away: 69² = 4900 − 70 − 69 = 4761.

Use it for: Areas of squares, Pythagoras in Class 7–9, and checking square tables.

Worked example: 71² = 5041

✏️ Practice

Work it out in your head or on paper, then tap your answer — or type it and press Check. Stuck? Press “Show me how”.

🏁 Lesson 10 test

20 questions. Check each answer, then go to the next one. Get 16 or more right to pass — and beat the clock: finish within 4 min.

🏅 Sign in with Google to earn the 💎 Square Shooter badge when you pass — and a certificate when you finish all 5 lessons of Part 2 · Speed multiplying. You can still take the test without signing in.

🖨️ Squares Trick Worksheet

• Worksheet set 1 (PDF)
• Worksheet set 2 (PDF)
• Worksheet set 3 (PDF)