CALCULATOR SKILLS
All calculations can be made without writing down intermediate steps. Writing down
intermediate steps introduces the possibility of error due to rounding. Below are some of
the more useful keys using the Casio Fx-82 calculator. If you have a different calculator you
will need to refer to the handbook.



Your calculator has several different modes for you to work in. You will
beMODE
be working in mode 1 which is comp (computation). Just press the mode
key then 1.
SHIFT
The shift key allows you to perform the operations shown in orange above
the main calculator keys. Just press shift, then the key under the operation that you
wish.
AC
DEL
All Clear except memory
Clears last number entered. If an operation
is entered incorrectly, simply enter the correct one.

The brackets keys enable you to perform an operation in the order in
which it is written without recording intermediate steps, or using the memory.

There are several memory facilities in the calculator. The calculator has memories M, A, B,
C, D, E, and F, all of which are shown in red on the keypad.
(
)
M shift
Always remember to clear the memory first by pressing Msh



M
+
STO
RCL
adds the number on display to memory M
stores a number into a memories A to F
recalls a number from a memory
e.g. To add 123, 456, 789 into memory M enter:
Shift AC
123 M+
456
M+
789 M+
To recall the answer enter
AC
1
Updated Feb 2013
RCL
M
AC
e.g. To enter 999 into memory A enter:
999
AC
To recall the number from memory A enter:
AC

ANS

STO
O
RCL
L
A
A
The answer key allows you to perform an operation on the previous
answer.
is used to enter numbers in scientific notation
EXP
e.g. To enter 8.4 X 10 5 : enter
8.4
EXP

There are several other Exponent or Power Keys. Do not get them mixed up with the
which multiplies a number by a power of 10.

raises a number x to the power of y.
X
Y
e.g. To find 53 enter:
X


5
(-)
X
2
3=
Y
squares any number e.g. To find 32 enter 3
X
1
x
( (some calculators use y ) finds the root of a number.
x
e.g. To find the 4th root of 16 enter: 4 4x

16 =
finds the cube root of a number
3
e.g. To find the cube root of 125 enter

3
125 =
finds the square root of a number
e.g. To find the square root of 49 enter:

2
-1
( some calculators use
) ) finds the reciprocal of a number
x
e.g. To find
1
enter: 32
32
-1
x
=
2
Updated Feb 2013
49 =
EXP

ab
allows you to enter fractions, to convert fractions to decimals and decimals
c
o
to fractions.
2 4
e.g. 1 
3 5
Enter: 1
ab
2
2
ab
c
3
c
To convert the answer to a decimal you press
ab
4
+
ab
5=
c
again
c
Scientific Calculators follow the standard order of operations BEDMAS
Examples

(2.64  1.38) 3 Enter (

3.6 2  8.5

Enter
1
3.75  4.16 2
2
2.64 -
3.6
X
Enter 3.75
2
x2
)
1.38
X
Y
3 =
8.5 =
-
4.16 4.16 = 2
x
+
=
ANS
Calculator skills exercises
1. a) (2.3+3.7)  (4.6+2.4)
b)
2.60
3.40  1.70
c)
4 23  2 52
d) 4 15  5 12
e)
3(65.3  (2.6+8.1))
f) 2 23  1 78
g)
1 15  1 14
h)
2. a)
c)
2
3
(use Brackets)
 15  2
3.6 10 4  2.3 103
b) 2.6 102  3.87 101
2.64 103  (1.6 10 4 )
d) 2.37 101  4.67 102
3
Updated Feb 2013
x-1
=
3. a) If p( x)  x 4  2 x 3  14 x 2  50 , find p(7.6) and p(10) .
b)
4. a)
If f ( x)  2 x 3  3x 2  4 x  1, find f (7.0) and f (1.6).
1977 24
b) (7.43 105 ) 3
c)
e) 3.654  4 165.2
f)
1
d)
g)
j)
5. a)
d)
20019
1
6 2
4 5
(6.2 10 )
5
3
4.7 103
26.5 4  3.77 2
48.2 2  5.614
1
5 4
h) (3.0 10 )
i) (2.8110 )
3.87  4.26
1
873.2
b)
1
6.023 10 23
e)
1
4.093 10 16
c)
1
0.0000362
1
1
8.0(5.5 10 11 ) 5
6. a)
2  3 4
b) (2  3)  4
c) 2  3   4
d)
2  32
e) (2  3)2
f) 2  70 10
h) 6  2  4
i) 6  (2  4)
g) 2  (70 10)
j) Study the order in which the operations are carried out in the following:
i)
( 8 + 4 )  ( 4  3 )
ii)
8 + 4 =  4  3 =
Ne 2
k) Calculate the value of
when:
2r
N  6.02 10 23e  4.80 1010 r  2.12 10 8
4
Updated Feb 2013
84
43
l) Calculate the value of
G  6.670  10 8
Gmn
when:
r2
m  1.67 10 24 n  9.1110 28 r  0.53 10 8
7. Evaluate:
a)
3.4 2  2.6 2
1.8 2  9.32
b)
4.6 2  3.8
d)
(7.4  1.36) 2
(2.78  3.41) 3
1.63  2.95  0.44
2.732
f)
4.8
3.9  0.133
3.2 6  2.55
1.7 4
h)
1
(3.8  2.6 2 ) 3
 4.8  3.7 
c) 

 2.9 1.2 
e)
g)
3
2
2
Calculator skills exercises solutions
1.
c) 11.2 or 11 1
a) -1.0
b) 1.53
e) 163.8
f) 4.54 or 4 13
g) 0.96 or
2.
a) 3.8  104
b) -0.361
c) 1.7 107
3.
a) 3500 6700
4.
a) 1.271  1079
b) 2.44  10-18
c) 17
d) 2.327
e) 636
f) 1.48  104
g) 9.2  10-17
h) 1.7  103
i) 0.073
j) 1.75
5.
5
24
(2sf)
h) 0.57 or
3
10
17
30
d) 0.0111
b) 570 5.9 (2sf)
a) 1.145  10-3
b) 2.441  1015
d) 1.660  10-24
e) 14
5
Updated Feb 2013
24
25
d) -1.3 or -1
c) 2.76  104
6.
7.
a) 14
b) 20
c) 20
d) 18
e) 36
f) 14
g) 14
h) 8
i) 0
j) 1.1
k) 3.27  1012
l) 3.6  10-42
a) 0.20
e) 0.56
b) 4.2
f) 3.0
c) 26
g) 4.9
6
Updated Feb 2013
d) 0.l5
h) 0.0022