Download Equivalent fractions

Concept : A fraction is an equal part of a whole
Primary 2
What is a
fraction ?
This is
ONE WHOLE cake
ONE part of
ONE WHOLE
If I cut the cake
right down the middle
I get two equal
pieces.
A fraction is
an EQUAL PART
of a WHOLE
TWO EQUAL parts of
ONE WHOLE
The numerator
tells us how many
EQUAL PARTS were
eaten, taken away, etc
Numerator
Denominator
The denominator tells
us how many EQUAL
PARTS are there in
ONE WHOLE
Concept Math Education Centre | No 1 Goldhill Plaza 03-01 S308899 | Tel : 62556335 | www.conceptmath.com
Concept : Equivalent fractions
Equivalent fractions have
The SAME VALUE.
We can find Equivalent
fractions by multiplying or
dividing both the numerator
and the denominator by the
same number.
A fraction is in its simplest
form when we cannot divide
the numerator and the
denominator by the same
number exactly.
Primary 3
=
=
Simplest form
Multiply by 2
X2
X2
=
=
X2
X2
Divide by 2 (Simplifying)
OR
÷2
÷2
=
=
÷2
÷2
Simplest
form
Concept Math Education Centre | No 1 Goldhill Plaza 03-01 S308899 | Tel : 62556335 | www.conceptmath.com
Concept : Fraction in its simplest form
To express a fraction in its
simplest form means to
reduce it so that the
numerator and denominator
are as small as they can
possibly be WITHOUT
changing the value of the
fraction (Equivalent
fractions).
Primary 3
How to express
a fraction in its
simplest form ?
Eg :
÷2
÷2
÷2
÷2
÷2
÷2
We divide the numerator
and denominator of a
fraction by the same
number to get an
equivalent fraction.
How do we know
if a fraction is
in its simplest form?
A fraction is in its simplest
form when we cannot divide
the numerator and the
denominator by the same
number exactly.
÷?
?
?
÷2
÷2
÷?
Equivalent fractions
Simplest form
Concept Math Education Centre | No 1 Goldhill Plaza 03-01 S308899 | Tel : 62556335 | www.conceptmath.com
Concept : Simplifying Mixed Number
Primary 4
If I cut one of the pizzas
I ordered 2 pizzas
into 8 equal parts
and eat half of the pizza,
I will have
of the pizzas left.
If I cut one of the pizzas
into 2 equal parts
and eat half of the pizza,
I will have
of the pizzas left.
To express a mixed number
in its simplest form,
look at its
numerator and denominator.
4 and ___.
8
They are ___
÷2
÷2
=
=
÷2
÷2
NOT
Simplest form
THINK
÷4
OR
What are the
common factors
of 4 and 8 ?
1 ___
2
They are ___,
and ___
4
And the
greatest
common factor
4
is ___.
=
÷4
simplest
form
simplest
form
Equivalent fractions
So,
=
(simplest form)
Concept Math Education Centre | No 1 Goldhill Plaza 03-01 S308899 | Tel : 62556335 | www.conceptmath.com
Comparing LIKE fractions (SAME DENOMINATORS)
Primary 2
Which is greater?
or
I cut a cake into
4 equal parts.
I ate 1 part.
I ate …......
of the cake.
I cut a cake into
4 equal parts.
I ate 3 parts.
I ate …......
of the cake.
Which is
a bigger
portion?
OR
THINK
Comparing LIKE fractions
(SAME DENOMINATORS)
The greater the NUMERATOR
the greater the value of the
fraction.
smaller
greater
Concept Math Education Centre | No 1 Goldhill Plaza 03-01 S308899 | Tel : 62556335 | www.conceptmath.com
Comparing fractions with same NUMERATORS
Primary 2
Which is greater?
or
I cut a pizza into
4 equal parts.
I ate 3 parts.
I ate …......
of the pizza.
I cut a pizza into
8 equal parts.
I ate 3 parts.
I ate …......
of the pizza.
Which is
a bigger
portion?
OR
THINK
Comparing fractions with
SAME NUMERATOR
The smaller the DENOMINATOR
the greater the value of the
fraction.
greater
smaller
Concept Math Education Centre | No 1 Goldhill Plaza 03-01 S308899 | Tel : 62556335 | www.conceptmath.com
Comparing UNLIKE fractions (DIFFERENT DENOMINATORS) Primary 3
Which is greater?
or
5
Change
UNLIKE fractions
(different denominators)
to
LIKE fractions
(same denominator)
5
Equivalent fractions
6
is greater than
5
THINK
Which is smaller?
1
3
or
3
8
Equivalent fractions
1
3
THINK
Equivalent fractions
8
24
3
8
is smaller than
9
24
Concept Math Education Centre | No 1 Goldhill Plaza 03-01 S308899 | Tel : 62556335 | www.conceptmath.com
Primary 4
Concept : Converting MIXED NUMBERS to IMPROPER fractions
+
+
How many
QUARTERS are
there
in 1 whole?
THINK
+
+
=
9
1 whole has 4 quarters.
2 wholes have 8 quarters.
8 quarters + 1 quarter = 9 quarters
Concept Math Education Centre | No 1 Goldhill Plaza 03-01 S308899 | Tel : 62556335 | www.conceptmath.com
Concept : Converting IMPROPER fractions to MIXED NUMBERS
11
Primary 4
How many
QUARTERS
make
in 1 whole?
THINK
+
+
+
3
+
3
=
3
4 quarters makes 1 whole.
8 quarters makes 2 whole.
11 quarters = 2 wholes + 3 quarters
Concept Math Education Centre | No 1 Goldhill Plaza 03-01 S308899 | Tel : 62556335 | www.conceptmath.com
When you add or subtract
fractions with the same
denominators,
you add or subtract the
numerators
while the denominators
stay the same.
Primary 2
How do I
Add and Subtract
fractions?
Eg
Concept : Addition of LIKE fractions (SAME DENOMINATORS)
+
=
+
=
=
=
(1 Whole)
Concept : Subtraction of LIKE fractions (SAME DENOMINATORS)
−
=
=
Concept Math Education Centre | No 1 Goldhill Plaza 03-01 S308899 | Tel : 62556335 | www.conceptmath.com
Concept : Addition of UNLIKE fractions
Before you add
fractions with the
different denominators,
change them into the
same denominators
THINK
+
=
Primary 3
How many
QUARTERS
are there
in one half?
=
=
x2
Different
Denominators
Same
Denominators
x2
+
+
=
=
Concept Math Education Centre | No 1 Goldhill Plaza 03-01 S308899 | Tel : 62556335 | www.conceptmath.com
Concept : Subtraction of UNLIKE fractions
Before you subtract
fractions with the
different denominators,
change them into the
same denominators
THINK
Different
Denominators
Same
Denominators
−
−
Primary 3
How many
QUARTERS
are there
in one half?
=
x2
x2
=
=
Concept Math Education Centre | No 1 Goldhill Plaza 03-01 S308899 | Tel : 62556335 | www.conceptmath.com