Reviewing what was studied about fractions .
Remember that :
(1) In each fraction, the number at the top is called " numerator "
and the number at the bottom is called "denominator".
Example : 2
 Number
11  Denominator
(2) Proper Fraction :
A fraction in which the number is smaller than denominator .
3
4
5
7
6
Example : ‫ ـــــــ‬, ‫ ـــــــ‬and ‫ ـــــــ‬are called
13
Proper fraction .
(3) Improper fraction :
A fraction in which the numerator is greater than or equal to the
denominator .
4
7
61
Example : ‫ ـــــــ‬, ‫ ـــــــ‬and ‫ ـــــــ‬are called improper fraction .
3
6
2
(4) Equivalent Fractions :
To find equivalent fractions, multiply or divide both of the
numerator and denominator by the same number . ( other than
Zero).
x2
2
4
Example : ‫= ـــــــ‬
‫ـــــــ‬
5
10
x2
(5) Simplifying the fraction :
To reduce ( simplify) a fraction to its simplest form , we divide
each of the numerator and the denominator by the greatest
possible common number :
÷4
4
Example : ‫ـــــــ‬
1
=
12
4= 2x2
12 = 2 x 2 x 3
H.C.F = 2 x 2 =4
÷4
‫ـــــــ‬
3
(6) Adding fractions :
When you are adding some fractions of the same denominator,
add the numerators and use the same denominator .
3
Example : ‫ ـــــــ‬+ ‫= ـــــــ‬
7
5
2
7
‫ـــــــ‬
7
(7) Subtracting fractions :
When you are subtracting two fractions of the same denominator
, subtract the numerators and use the same denominator.
3
2
1
Example : ‫ ـــــــ‬- ‫ـــــــ = ـــــــ‬
7
7
7
==============================================
Exercise 1:
1- Write each of the following whole numbers as an improper
fraction :
(a) 6 =
(c) 10 =
….
1
….
3
.….
(b) 16 =
2
12
(d) 4 =
….
Units of measuring length
*The meter(m) = 100 centimeters (cm)
* 1 meter(m) = 10 decimeter(dm)
* 1centimetres(cm) = 10 decimeter(dm)
* The centimeters(cm) = 10 millimeters(mm)
* The kilometer(km) = 1000 meters(m)
* Perimeter of a square = side length  4
* perimeter of a rectangle = ( length + width )  2
1000
10
10
10
km
m.
Dm.
Cm.
mm.
÷1000 ÷10
÷10
÷10
Examples
3 m. = 300cm.
3.5m. = 350cm.
6.5cm = 65cm.
5dm. = 50cm.
15dm. = 15cm. = 150mm.
,
,
,
,
,
4m. = 400cm.
3 cm. = 30mm.
4m.= 400cm.= 4000mm.
3dm. = 30cm. = 300mm.
8km. = 800m. = 80dm.
Note:
*The perimeter of polygon equals the sum of it’s side lengths.
4cm.3 cm
5cm.
5 cm
3cm
the perimeter of =3cm. +4cm. +5cm=12cm
The Area
* The area of square = side length  itself
* The area of rectangle = length  width
*Notes :
m² = 1m 1m = 100cm  100 cm = 10000cm²
dm² = 1dm 1dm = 10cm 10cm = 100cm²
km² = 1km 1km = 1000m 1000m = 1000 000 m²
1000 000
100
100
𝒌𝒎𝟐
𝒎𝟐 .
𝑫𝒎𝟐 .
÷ 1 000 000
÷ 100
100
𝑪𝒎.𝟐
÷100
𝒎𝒎𝟐
÷100
The Time
X7
Week
X 24
Day
÷𝟕
X 60
Hour
÷ 24
X 60
Minute
÷ 60
second
÷ 60
Remember that :Even numbers :- (0 , 2 , 4 , 6 , 8 , 10 , …………..)
Odd numbers :- (1 , 3 , 5 , 7 , 9 , 11 , ………….. )
Prime number :- number has only two factors one and itself
(2 , 3 , 5 , 7 , 11 , 13 , …………..)
Notes :
* The prime number is divisible only by 1 and itself.
* 2 is the smallest Prime number.
* 2 is only even prime number.
* All prime numbers are odd except 2.
* 1 is not a prime number because it has only one factor.
* find H.C.F and L.C.M for 24 , 18
24
2
18 2
24= 2X2X2X3
12
2
9
18= 2X
6
2
3 3
H.C.F=2X3 =6
3
3
1
L.C.M=2X2X2X3X3=72
1
3
3X3