1. MTH 3-06a 10-Jan-16Compiled by Mr. Lafferty Maths Dept. Powers & Roots www.mathsrevision.com Squares, Cubes and Powers (Indices) Square Roots and Cube Roots

2. MTH 3-06a 10-Jan-16Compiled by Mr. Lafferty Maths Dept. Starter Questions www.mathsrevision.com

3. MTH 3-06a 10-Jan-16Compiled by Mr. Lafferty Maths Dept. Squaring a Number www.mathsrevision.com Learning Intention Success Criteria 1.To understand what is meant by the term power of a number. 1.We are learning the term about powers of a number’. about powers of a number’. 2.Be able to calculate powers of a number squares both mentally and using the calculator.

4. MTH 3-06a 10-Jan-16Compiled by Mr. Lafferty Maths Dept. www.mathsrevision.com Square of a Number To square a number means to : “Multiply it by itself” means 9 x 9 = 81 Example : means 10 x 10 = 100 9 2 10 2

5. MTH 3-06a 10-Jan-16Compiled by Mr. Lafferty Maths Dept. www.mathsrevision.com Cube of a Number To cube a number means to : “Multiply it by itself and then itself again” means 2 x 2 x 2 = 8 Example : means 4 x 4 x 4 = 64 2 3 4 3

6. MTH 3-06a 10-Jan-16Compiled by Mr. Lafferty Maths Dept. www.mathsrevision.com Index of a Number means 2 x 2 x 2 x 2 x 2 = 2 5 32 anan n is called the index number a is called the base number Example :

7. 10-Jan-16Mr. Lafferty@mathsrevision.com 9 1 0 0 0-8 2 1 6 2 5 61 NON - CALCULATOR

8. MTH 3-06a 10-Jan-16Compiled by Mr. Lafferty Maths Dept. www.mathsrevision.com Area of Square = 7 2 = 49cm 2 Example :Find the area of a square with length 7cm. Area of a square is A = l x l = l 2 A = l 2 l cm

9. 10-Jan-16 Compiled by Mr. Lafferty Maths Dept. Special button on the calculator

10. MTH 3-06a 10-Jan-16Created by Mr. Lafferty Maths Dept. Now try TJ3b Ex 1 Ch1 (page 8) www.mathsrevision.com Powers & Roots

11. MTH 3-06a 10-Jan-16Compiled by Mr. Lafferty Maths Dept. www.mathsrevision.com Square Root of a Number You now know how to find : We can ‘undo’ this by asking “which number, times itself, gives 81” 9 2 = 9 x 9 = 81 From the top line, the answer is 9 This is expressed as : “ ““ “the SQUARE ROOT of 81 is 9” or in symbols we write :

12. MTH 3-06a 10-Jan-16Compiled by Mr. Lafferty Maths Dept. www.mathsrevision.com Cube Root of a Number You now know how to find : We can ‘undo’ this by asking “which number, times itself, times itself again gives 8” 2 3 = 2 x 2 x 2 = 8 From the top line, the answer is 2 This is expressed as : “the CUBE ROOT of 8 is 2” or in symbols we write :

13. MTH 3-06a 10-Jan-16Compiled by Mr. Lafferty Maths Dept. www.mathsrevision.com Roots of a Number means 4 x 4 = 16 Example : 4 2 so √16 = 4 means 5 x 5 x 5 = 1255 3 so 3 √125 = 5

14. 10-Jan-16Mr. Lafferty@mathsrevision.com 8 6 1 1 43 7 NON - CALCULATOR

15. MTH 3-06a 10-Jan-16Compiled by Mr. Lafferty Maths Dept. www.mathsrevision.com Length of a Square = √400 Example :Find the length of the square. Area of a square is A = l x l = l 2 l = √A l cm 400cm 2 l = 20 cm

16. 10-Jan-16 Compiled by Mr. Lafferty Maths Dept. Special button on the calculator

17. MTH 3-06a 10-Jan-16Created by Mr. Lafferty Maths Dept. Now try TJ3b Ex 2 Ch1 (page 10) www.mathsrevision.com Powers & Roots Have you updated your Learning Log ?