Fractions(2).pdf mathematics grade 7 educ

Math

1. Fractions
Ms. Lalaine B. Abing

2. •
is a part of a whole.
•
is a rational number that can be written in
the form of a/b, where a is the numerator
and b is the denominator.

3. Three Kinds of Fractions
•
Proper Fraction - the numerator is less
than the denominator
Examples: 1/2, 1/3, 3/8, 2/5, ...
•
Improper Fraction - the numerator is
greater than the denominator
Examples: 4/3, 8/5, 10/3, 7/4, ...
•
Mixed Fraction - is composed of a whole
number and a fraction
Examples: 2 1/3, 9 2/5, 4 1/2, 10 1/5, ...

4. How to Simplify Fraction?
To reduce fraction to its lowest terms,
1. Find the Greatest Common Factor (GCF) of
the numerator and denominator.
2. Divide both the numerator and denominator
by their GCF.

5. Example:
Reduce 30/35 to lowest term.
Solution:
30 = 2
●

3
●

5
35 = 5
●

7
GCF = 5
30/35 = 6/7
Therefore, 30/35 is 6/7 when reduced to
lowest terms.

6. Classifications of Fractions
•
Similar Fractions - have the same
denominators
•
Dissimilar Fractions - have unlike
denominators

7. There are techniques that you can use
when comparing and ordering fractions.
,
7
6
,
7
5
,
7
4
,
7
3
and
1.
When the denominators are the same
In the fraction with the bigger
numerator has a greater value.
Thus,
2.
When the numerators are the same
In the fraction with the smaller
denominator has a greater value.
Thus,
.
7
3
7
4
7
5
7
6



,
6
5
,
5
5
,
4
5
,
3
5
.
6
5
5
5
4
5
3
5




8. 3.
When neither the numerators nor the
denominators are the same, use the
comparison property for rational numbers.

9. COMPARISON PROPERTY FOR
RATIONAL NUMBERS
,
d
c
and
b
a
For any rational numbers with b>0 and
d>0:
1. if then ad<bc
2. if ad<bc, then
Examples:
1.
2.
,
d
c
b
a

d
c
b
a

5
4
3
2
and
6
5
4
3
and

10. How to Add Fractions?
To add fractions with the same
denominator, simply add or subtract the
numerators. The denominator remains the
same.
Examples:
1. 1/3 + 1/3 = 2/3
2. 2/5 + 1/5 = 3/5

11. How to Subtract Fractions?
To subtract fractions with the same
denominator, simply add or subtract the
numerators. The denominator remains the
same.
Examples:
1. 3/8 - 2/8 = 1/8
2. 5/6 - 1/6 = 4/6 or 2/3

12. How about these?
1. 2/3 + 1/2
2. 5/6 + 2/5
3. 1/2 - 1/8
4. 1/14 - 1/7
= 4/6 + 3/6 = 7/6
= 25/30 + 12/30 = 37/30
= 4/8 - 1/8 = 3/8
= 1/14 - 2/14 = -1/14

13. To add or subtract fractions with different
denominators, convert the fractions to
equivalent forms with the same denominator.
This requires looking for the least common
denominator (LCD) of the fractions.