Finding and Estimating Square Roots

1. Section 9.3 Finding and Estimating Square Roots

2. Questions What is a perfect square? Perfect Square: Numbers with square roots that are whole numbers. 1×1 = 1 2×2 = 4 3×3 = 9 4×4 = 16 5×5 = 25 6×6 = 36 7×7 = 49 8×8 = 64 9×9 = 81 10×10 = 100 11×11 = 121 12×12 = 144 15×15 = 225 25×25 = 625

3. Questions What is a square root? Square Roots: A number that, when multiplied by itself, gives the original number. because 9 × 9 = 81

4. Questions About Square Roots: If there is no sign in front of a square root, then the answer should be positive . A − or ± in front of the square root tells the sign.

5. Questions Simplify each expression:

6. Questions What’s the difference between rational and irrational numbers? Rational Numbers: whole numbers fractions terminating or repeating decimals integers 3, 25, 197 0, -4, 17 perfect squares

7. Questions What’s the difference between rational and irrational numbers? Irrational Numbers: non-terminating AND non-repeating decimals square roots of numbers that are NOT perfect squares

8. Questions Tell whether each expression is rational or irrational : irrational irrational rational rational

9. Questions How do you estimate a square root? Estimate Square Roots: Find the perfect square larger and smaller than the given number. Take the square roots. smaller larger between 8 and 9

10. Questions Between what two consecutive integers is each square root? smaller larger between 5 and 6 smaller larger between -11 and -10