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Year 9 Maths — Squares and square roots

Square whole numbers and find the square roots of perfect squares.

Name: ________________________

Before you start

Every whole number from zero to twenty-five sits on this line. Find 1, 4, 9, 16 and 25 on it, and look at the gaps between them.

0510152025

The gaps go 3, then 5, then 7, then 9 — the perfect squares spread out as you go, which is why so few numbers have a whole square root.

  1. 1.√225 = ?

  2. 2.Which of these is a perfect square?

    • a) 200
    • b) 250
    • c) 196
    • d) 150

  3. 3.√144 = ?

  4. 4.Match each number to its square root.

    • 36
    • 100
    • 121
    • 400
    • 625
    • 10
    • 20
    • 25
    • 11
    • 6

  5. 5.17² = ?

  6. 6.Sort each number by whether it is a perfect square.

    Groups: Perfect square · Not a perfect square

    • 49
    • 81
    • 64
    • 50
    • 99
    • 70

  7. 7.A square garden has an area of 169 square metres. How long is each side, in metres?

  8. 8.√0.25 = ?

Answer key — Year 9 Maths — Squares and square roots

  1. 1. 15
  2. 2. c) 196
  3. 3. 12
  4. 4. 36 → 6; 100 → 10; 121 → 11; 400 → 20; 625 → 25
  5. 5. 289
  6. 6. 49 → Perfect square; 64 → Perfect square; 81 → Perfect square; 50 → Not a perfect square; 70 → Not a perfect square; 99 → Not a perfect square
  7. 7. 13
  8. 8. 0.5