“Oh GOSH! Reflecting on Hackteria's Collaborative Practices in a Global Do-It...
chapter1-140219121333-phpapp02.pdf
1. CHAPTER 1 :
Fundamental Operation
of Arithmetic
1.1 Fraction
1.2 Ratio and Proportion
1.3 Percentage
2. Two numbers separated by a horizontal or
sloping line.
E.g. Two seventh = 2/7 =
7
2
Types of fraction
Types Definition Examples
Proper fraction Numerator < denominator
Improper fraction Numerator = or >
denominator
Mixed fractions Whole number + common
fraction
Equivalent fractions Two fractions that have
equals values
1.1 FRACTION WHAT IS
FRACTION?
Denominator, D
Numerator, N
3. MIXED
Multiply the whole number by D,
add N. Place the total over N.
IMPROPER
Divide N by D as far as possible
and express remainder as a proper fraction
1.1 FRACTION Conversion
improper to
mixed
4. 1. ADDITION & SUBTRACTION
Same Denominators
Just add / minus the numerator
Different Denominators
Find a common denominator, then add / minus and
simplified the answer to the lowest term.
Example: Evaluate the followings;
5
2
5
4
3
2
d)
3
2
5
2
c)
5
1
7
3
b)
5
6
5
3
5
1
a)
+
−
+
+
+
1.1 FRACTION
OPERATION ON FRACTIONS
5. 1. Add together :
5
1
3
3
1
4
2
1
5
e)
5
3
4
3
2
3
d)
3
1
5
2
8
3
c)
9
1
8
5
b)
5
1
3
2
a)
+
+
+
+
+
+
+
PRACTICE 1
5
3
3
2
1
7
e)
4
3
2
3
1
5
d)
3
1
3
16
7
5
c)
5
2
4
3
b)
4
1
3
2
a)
−
−
−
−
−
2. Subtract the following:
6. 1.1 FRACTION
OPERATION ON FRACTIONS
s
q
r
p
s
r
q
p
×
×
=
×
r
q
s
p
r
s
q
p
s
r
q
p
×
×
=
×
=
÷
2. MULTIPLICATION
Product of the numerators
divide by the product of the
denominators.
Can be simplified if possible
before multiplying.
Mixed fractions have to be
converted into improper
fractions before multiply.
3. DIVISION
Invert the divisor and
change the division sign to
multiplication.
8. 1.1 FRACTION
OPERATION ON FRACTIONS
n
n
n
b
a
b
a
=
9
4
81
16
81
16
=
=
b
a
b
a
=
4. POWERS
Raise both the numerator &
the denominator to that
power.
Example;
5. SQUARE ROOTS
Invert the divisor and
change the division sign to
multiplication.
Example;
125
8
5
2
5
2
3
3
3
=
=
9. 1.1 FRACTION
OPERATION ON FRACTIONS
with.
start
to
3.60
RM
had
girl
The
cents
360
90
4
1
cents
90
4
1
4
3
1
∴
=
×
=
=
=
−
20
7
20
13
20
20
13
1
Drink
)
2
=
−
=
−
=
6. PRACTICAL APPLICATION
A girl spends 3/4 of her pocket money and has 90cents left. How
much did she have to start with?
20
13
20
5
8
4
1
5
2
Food
)
1
=
+
=
+
=
A group, of school children went to a hamburger bar, 2/5 of them bought
hamburgers only, 1/4 bought chips only and the remainder bought drinks only
What fraction bought food?
What fraction bought drinks?
10. 1. Jane takes 5 ¾ minutes to iron a blouse. How
many blouses can she iron in 23 minutes?
2. The profit of a business are RM 29 000. It is
shared between two partners A & B. If A
receives 9/20 of the profits, how much money
does B receive?
3. A man sells his car for RM 16 200 and as a
result, loses one tenth of the price he paid for it.
What price did he pay for it?
4. 5/8 of a fence has been built. If there is still 40
feet to be built, how long will the fence be?
5. A man left three eight of his money to his wife &
half the remainder to his son. The rest was
divided equally between his five daughters.
Determine what fraction of the money each
daughter received.
PRACTICE 3
11. Comparison of 2 numbers or quantities as quotient.
Represent by x/y or x : y.
Generally reduced to lowest terms like fraction (by
dividing the HCF of the numbers).
Derived from quantities measured in the same units
Its just number, don’t have unit.
Its express the relationship between 2 or more
factors (or numbers)
1.2 RATIO &
PROPORTION
WHAT IS
RATIO ?
12. E.g. Simplify the ratio 200g : 1 kg (different units)
= 200g : 1000g
= 1 : 5
Example: Expressed the following ratio to the lowest
term;
1.2 RATIO &
PROPORTION
WHAT IS
RATIO ?
2
2
mm
10
:
cm
10
d)
13
8
to
13
12
c)
8
3
:
8
5
b)
2
3
52
78
52
:
78
a)
=
=
=
13. The equality of 2 ratios
E.g. 5 : 2 = 25 : 10
To solve problems dealing with proportion, we use
cross multiplication.
Types of proportion:
1.2 RATIO &
PROPORTION
WHAT IS
PROPORTION ?
1. Direct proportion
If increase or decrease at the
same rate.
E.g. If we buy rice at RM 2 for 2
kg, then we expect to pay RM 4
for 4 kg.
2. Inverse proportion
If an increase (decrease) in one
quantity produces a decrease
(increase) in a second quantity
in the same time.
E.g. 5 men building a wall take
20 days. If 4 men, it will take
only 25 days.
14. Examples:
1. Find the value of x for 5 : 25 = 3 : x.
2. If a : b = 5 : 3, find
a. b : a
b. a : (a – b)
c. b : (a + b)
d. (a – b) : (a + b)
1. If a : c = 3 : 4, and a : b = 4 : 5, find b : c
15
75
5
3
25
5
=
=
⇒
=
x
x
x
1.2 RATIO &
PROPORTION
WHAT IS
PROPORTION ?
15. Express a quantity as the number of parts in 100 parts.
Written as fraction, e.g. 20 percent = 20 % = 20/100 = 0.20
Conversion:
Fractions Percentage Decimal
x 100% ÷ 100%
x 100%
÷ 100%
Then move dec. point
2 places to the left
Then move dec. point
2 places to the right
1.3 PERCENTAGE WHAT IS
PERCENTAGE
?
16. Example: Express each number as a fraction, decimal
and percent.
a. 86% b. 5.6%
c. 8 ½% d. 0.025
e. 1.5 f. 9/8
g. 17/1000
1.3 PERCENTAGE