Using the CASIO fx-260 on the GED Mathematics Test

Using the CASIO® fx-260 on the GED® Mathematics Test
When you take the GED® Mathematics Test, you will be given a scientific calculator to use for the first part
of the test. This calculator, the CASIO fx-260, has many more keys than you will actually need on
the test. The keys that you will use most often are shown in the diagram below and on the next page.
You may have these same functions on a calculator that you have at home. Study the key
locations on these diagrams. If possible, obtain this type of calculator in advance so that you can
practice using it before you take the test.
Square Key
Power On
Fraction Key
Sign Change Key
Backspace Key
Memory Recall
C — Clear
AC — All Clear
Parentheses Keys
Operation Keys
Memory Plus
Decimal
Point
Exponen
t
Key
Basic Operations
Equals Key
Special Keys
The CASIO fx-260 follows the order of
operations.
If you make a mistake while entering a
calculation, you can press:
To evaluate an expression, enter the numbers
and operations from left to right. Use
parentheses to show that one operation must
be performed before another.
to backspace and delete digits
C to clear only the last operation performed
AC to clear everything and start the
calculation over
Evaluate: 34
Enter: 3 4
Scientific Notation
27
2
5
7
5
Evaluate: (34 + 27) 5 =
2 7 -)]
Enter: [(- 3 4
169.
5
305.
In the first example, the multiplication step
was performed first even though the addition
step was entered first. In the second example,
the parentheses instructed the calculator to
add before multiplying.
You can enter a number in scientific notation
using the EXP key. First, enter the mixed
decimal portion of the number. Then press
EXP and enter the power of ten by which the
mixed decimal is multiplied.
Example: What is the value of 1.6 107?
Enter: 1 . 6 EXP 7
16000000.
Note: The EXP key replaces the
multiplication symbol in the problem.
Copyright © 2001. KET. All rights reserved.
GED® and GED Testing Service® are trademarks of the American
Council on Education® and may only be used with express permission.
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The CASIO fx-260 assigns two functions to some keys. The second function labels are written
in yellow print above the keys. To use a second function, press SHIFT and then the desired key.
The second functions you may need on the GED® Mathematics Test are shown in the diagram below.
Square Root Key
The CASIO fx-260
can operate in
different modes.
When you press
AC , the display
should indicate
DEG as shown. If
you see any other
mode displayed as
you work, press AC
and begin again.
Indicates the
current mode
Shift Key
Fraction Key
Memory In Key
Power Key
Memory Minus Key
Percent Key
Squares and Square Roots
Percent
While working with formulas and evaluating
expressions, you may need to raise a number
to a higher power.
To access the percent function on this
calculator, you must first press SHIFT. Study
how the percent key is used in these examples.
To square a number, enter the number and
press x2.
Example: What is 42% of $1200?
4 2 SHIFT %
Press: 1 2 0 0
Display:
504.
Example: What is the square of 26?
Press: 2 6 x2
Display:
676.
To raise a number to a higher power, enter the
number, press xy, and enter the power.
Example: What is the value of 65?
Press: 6 xy 5
7776.
To find the square root of a number, enter the
number and press SHIFT
.
Example: Find the square root of 576.
Press: 5 7 6 SHIFT
Display:
24.
Example: What percent of 224 is 56?
2 2 4 SHIFT %
Press: 5 6
Display:
25.
Answer: 56 is 25% of 224.
Example: A store paid $80 for a coat. The
store sold the coat for the cost plus 40%.
What was the selling price of the coat?
Press: 8
Display:
0
4
0
SHIFT
%
112.
Answer: The coat sold for $112.
Example: A $32 purchase is discounted 20%.
What is the sale price of the purchase?
Press: 3 2
2 0 SHIFT %
Display:
25.6
Answer: The sale price is $25.60.
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Using the Fraction Keys
The fraction keys on your calculator can help you save time on the
GED® Mathematics Test. The fraction keys allow you to enter fractions
and whole numbers without first converting the fractions to decimals.
In the display window, the numerator and the denominator of a
fraction are separated by the symbol .
Example: Reduce the fraction
Press: 8 5 a bc 1 0 2
Display:
5 6.
Answer:
85
102
reduces to
85
102
The display shows the
mixed fraction: 2 45 .
to lowest terms.
5.
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You can also use the calculator to perform operations with fractions.
Example:
7
10
?
3
4
Press: 7 a bc 1 0
1 9 20.
3 a bc 4
You can change the mixed fraction to an improper fraction.
Press: SHIFT d/c
Display:
29 20.
Answer: The sum of
7
10
and
3
4
is 1 9 or
20
29
20
.
Using the Memory Features
The memory keys on the CASIO fx-260 perform the following functions:
Memory In
Puts the displayed number in the memory.
M
Memory Plus
Adds the displayed number to the memory.
SHIFT M
Memory Minus
Subtracts the displayed number from the memory.
MR
Memory Recall
Displays the contents of the memory.
SHIFT
Min
The memory features are useful when a problem has more than one part. To make sure the
memory is empty before you begin, press the ON key.
Example: Zoila buys 3 jars of tomato sauce for $1.15 each and 2 pounds of ground beef for
$2.79 each. She has a 75-cents-off coupon. What is the cost of the food?
1.
Store the cost of the tomato
sauce in the memory.
Press: 1
.
1
5
3
SHIFT
2.
Find the cost of the ground beef
and add it to the memory.
Press: 2
.
7
9
2
M
3.
Subtract the coupon amount.
Press: .
7
5
SHIFT
4.
Use memory recall to find
the answer.
Press:
MR
Display:
Min
M
8.28
Answer: The cost of the food is $8.28.
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