using a calculator 2

www.MoreThanMaths.com

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


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!


The x2 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


The x2 key

• Try pushing these keys:

• You should see the answer 16.

• What calculation do you think the x2 button does?

• Try changing the number 4 to something else and do the calculation again.

• What happens now?

4 X 2 =


The x2 key

• Can you work these out on your calculator?

(a) 52

(b) 82

(c) 252

(d) 452

(e) 1202


The x2 key : Answers

• How many did you get right?(a) 52 = 25(b) 82 = 64(c) 252 = 625(d) 452 = 2025(e) 1202 = 14400


The yx 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 ^


The yx key

• Try pushing these keys.

• What answer do you get?

• What calculation might have given that answer?

4 y x 2 =


The yx 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 =


The yx key

• These buttons work out powers or exponents

• To calculate 53, push these keys:

y x X y ^

5 y x 3 =


The yx 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) 34 (correct answer: 81)

(b) 25 (correct answer: 32)

(c) 63 (correct answer: 216)

(d) 124 (correct answer: 20736)

(e) 155 (correct answer: 759375)


The √_

key• Your calculator should have a button like this:

• Can you find this key on your calculator?

√_


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 =√_


The √_

key• Now try these:

• What calculation do you think the √_

button does?

2 =

√_ 5

1 =

√_ 6


The √_

key

• The √_

button is used to calculate square roots

• Did you manage to work that out for yourself?

√_


The √_

key

• Can you work these out on your calculator?

(a)

(b)

(c)

(d)

(e) 529

121

400

225

64


The √_

key: answers

• How many correct answers did you get?

(a) = 8

(b) = 11

(c) = 15

(d) = 20

(e) = 23529

121

400

225

64


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.

x yx


Finding roots

• Try pushing these keys.

• What answer do you get?• What calculation might have given that

answer?

3 8 =x


Finding roots

• Now try pushing these keys.

• What answer do you get?• What calculation might have given that

answer?

63 = 4x


Finding roots

• Try it again using these keys.

• What answer do you get?• Can you work out what this button does?

14 = 6x


Finding roots

• This will calculate the cube root of 64:

• = 4

• Did you manage to work that out for yourself?

x 63 = 4

3 64

x


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

using a calculator 2

Education