Using a calculator: powers, roots and brackets

The Maths Habit

Mo types the code into a door lock. Will the door open?

The code
2580
Mo presses
5280

No. The keys are right, but the order is wrong.

Square
A number multiplied by itself.
x2
Cube
Three of the same number multiplied together.
x3
Square root
The number you square to get it.
√
Brackets
Two curved lines round part of a calculation. That part is worked out first.
()
Display
The screen on a calculator. It shows the answer.
 

x2after
√before
x2+=
 
  1. 1Spot the special key.x² and x³ go after the number. √ goes before it.
  2. 2Write the keys in order.End with =.
  3. 3Copy the display.Write every digit.

Which special key do you need?

1Spot the special key.2Write the keys in order.3Copy the display.
92x2
√81√
43x3

Work out 152 + 64

1Spot the special key.
x2
2Write the keys in order.
15x2+64=
3Copy the display.
289

Work out √361

1Spot the special key.
√
2Write the keys in order.
√361=
3Copy the display.
19

Work out 152 + 64

1Spot the special key.
x2
2Write the keys in order.
15x2+64=
3Copy the display.
289
1Spot the special key.2Write the keys in order.3Copy the display.

Work out 143

1Spot the special key.
x3
2Write the keys in order.
14x3=
3Copy the display.
2744

Work out 152 + 64

1Spot the special key.
x2
2Write the keys in order.
15x2+64=
3Copy the display.
289
1Spot the special key.2Write the keys in order.3Copy the display.

Work out 222 − 99

1Spot the special key.
x2
2Write the keys in order.
22x2−99=
3Copy the display.
385

Work out 152 + 64

1Spot the special key.
x2
2Write the keys in order.
15x2+64=
3Copy the display.
289
1Spot the special key.2Write the keys in order.3Copy the display.

Work out 70 + √256

1Spot the special key.
√
2Write the keys in order.
70+√256=
3Copy the display.
86

1Spot the special key.2Write the keys in order.3Copy the display.

1Work out 312

1Spot the special key.
x2
2Write the keys in order.
31x2=
3Copy the display.
961

2Work out √484

1Spot the special key.
√
2Write the keys in order.
√484=
3Copy the display.
22

3Work out 113

1Spot the special key.
x3
2Write the keys in order.
11x3=
3Copy the display.
1331

4Work out 132 + 57

1Spot the special key.
x2
2Write the keys in order.
13x2+57=
3Copy the display.
226

()
(+)×=
 
  1. 1Spot the special key.Press ( and ) where the brackets are.
  2. 2Write the keys in order.End with =.
  3. 3Copy the display.Write every digit.

Do you need the bracket keys?

1Spot the special key.2Write the keys in order.3Copy the display.
3 × (4 + 5)Yes
3 × 4 + 5No
(6 + 2) × 5Yes

Work out (27 + 18) × 4

1Spot the special key.
()
2Write the keys in order.
(27+18)×4=
3Copy the display.
180

Work out (93 − 39) ÷ 6

1Spot the special key.
()
2Write the keys in order.
(93−39)÷6=
3Copy the display.
9

Work out (27 + 18) × 4

1Spot the special key.
()
2Write the keys in order.
(27+18)×4=
3Copy the display.
180
1Spot the special key.2Write the keys in order.3Copy the display.

Work out 5 × (46 + 29)

1Spot the special key.
()
2Write the keys in order.
5×(46+29)=
3Copy the display.
375

Work out (27 + 18) × 4

1Spot the special key.
()
2Write the keys in order.
(27+18)×4=
3Copy the display.
180
1Spot the special key.2Write the keys in order.3Copy the display.

Work out 336 ÷ (5 + 9)

1Spot the special key.
()
2Write the keys in order.
336÷(5+9)=
3Copy the display.
24

Work out (27 + 18) × 4

1Spot the special key.
()
2Write the keys in order.
(27+18)×4=
3Copy the display.
180
1Spot the special key.2Write the keys in order.3Copy the display.

Work out (64 − 19) × 7

1Spot the special key.
()
2Write the keys in order.
(64−19)×7=
3Copy the display.
315

Using a calculator: powers, roots and brackets worksheet, page 1

Using a calculator: powers, roots and brackets worksheet, page 2

Answer sheet

Are the keys right?
Thumbs up: right. Thumbs down: wrong.

  1. 62 6×2=

    Wrong: press x², not × 2

  2. √49 49√=

    Wrong: √ goes first

  3. (2 + 3) × 4 (2+3)×4=

    Right

  4. 10 ÷ (1 + 4) 10÷1+4=

    Wrong: it needs the brackets

  5. 53 5x3=

    Right

  1. Work out 2.62 + 3.7

    10.46

  2. Work out √(16 + 9). Press √ then ( 16 + 9 ) then =.

    5

  3. Work out 17.4 + 6.64.3 − 1.1. Put each part in brackets.

    7.5

  1. Work out 212 + 59

    500
    1Spot the special key.x22Write the keys in order.x23Copy the display.

  2. Work out (35 − 17) × 4

    72
    1Spot the special key.2Write the keys in order.3Copy the display.

  3. Work out 300 − √289

    283
Exit tickets to print