This document provides instructions for using the power and root keys on a scientific calculator. It explains that the x^2 key is used to calculate squares, the y^x key is used to calculate powers or exponents, and the √ key is used to calculate square roots. The document includes examples of calculations and tests the reader's understanding by having them calculate various powers and roots.

1. We Are Learning: How to use the power keys on a scientific calculator (powers are also known as indices or exponents) How to use the root keys on a scientific calculator

2. Important Advice: Different makes and models of calculator have different designs of keys. Yours might not look like the examples in this presentation. Ask your teacher for advice about how your calculator works. This presentation was made for students in the United Kingdom. I’ve tried to include alternative terms for students from outside the UK –sorry if there are any problems!

3. The x 2 key Your calculator probably has a button like this: Can you find this on your calculator? Watch out! It might be a second function, if it is you will need to push shift or 2ndF to make it work. X 2

4. The x 2 key Try pushing these keys: You should see the answer 16. What calculation do you think the x 2 button does? Try changing the number 4 to something else and do the calculation again. What happens now? 4 X 2 =

5. The x 2 key Can you work these out on your calculator? (a) 5 2 (b) 8 2 (c) 25 2 (d) 45 2 (e) 120 2

6. The x 2 key : Answers How many did you get right? (a) 5 2 = 25 (b) 8 2 = 64 (c) 25 2 = 625 (d) 45 2 = 2025 (e) 120 2 = 14400

7. The y x key Can you find a button your calculator that looks like one of these? They all do the same thing, but some makes of calculator use different designs to others. Watch out! This might be a second function, if it is you will need to push shift or 2ndF to make it work. y x X y ^

8. The y x key Try pushing these keys. What answer do you get? What calculation might have given that answer? 4 y x 2 =

9. The y x key Now try pushing these keys. What answer do you get? What calculation might have given that answer? Try it again with some different numbers. Can you work out what this button does? 2 y x 3 =

10. The y x key These buttons work out powers or exponents To calculate 5 3 , push these keys: y x X y ^ 5 y x 3 =

11. The y x key: Test Yourself Check that you know how to use this key by doing these calculations. If you get the correct answer, then you are using your calculator correctly. (a) 3 4 (correct answer: 81) (b) 2 5 (correct answer: 32) (c) 6 3 (correct answer: 216) (d) 12 4 (correct answer: 20736) (e) 15 5 (correct answer: 759375)

12. The √ _ key Your calculator should have a button like this: Can you find this key on your calculator? √ _

13. The √ _ key Try pushing these keys. You should see the answer 3. What calculation do you think the √ _ button does? HINT: Some calculators work in a slightly different way. If you don’t get the answer 3, try keying 9 in first and then press √ _ 9 = √ _

14. The √ _ key Now try these: What calculation do you think the √ _ button does? 2 = √ _ 5 1 = √ _ 6

15. The √ _ key The √ _ button is used to calculate square roots Did you manage to work that out for yourself? √ _

16. The √ _ key Can you work these out on your calculator? (a) (b) (c) (d) (e)

17. The √ _ key: answers How many correct answers did you get? (a) = 8 (b) = 11 (c) = 15 (d) = 20 (e) = 23

18. Finding roots Can you find a button your calculator that looks like one of these? Watch out! It might be a second function, if it is you will need to push shift or 2ndF to make it work.

19. Finding roots Try pushing these keys. What answer do you get? What calculation might have given that answer? 3 8 =

20. Finding roots Now try pushing these keys. What answer do you get? What calculation might have given that answer? 6 3 = 4

21. Finding roots Try it again using these keys. What answer do you get? Can you work out what this button does? 1 4 = 6

22. Finding roots This will calculate the cube root of 64: = 4 Did you manage to work that out for yourself? 6 3 = 4

23. Summary: You should know how to use your calculator to find squares and square roots You should know which key calculates powers (exponents) and how to use it You should know which key calculates roots and how to use it