Transcript Comparing Fractions

0
1
2
3
4
5
0
1
2
3
4
5
0
1
4
2
4
3
4
1
0
0
2
3
1
3
1/5
2/5
3/5
1
4/5
1
0
2
4
1
4
0
1
6
2
6
3
6
3
4
4
6
1
5
6
1
0
0
<
1
3
<
2
3
<
1
< 1/6 < 2/6 < 3/6 < 4/6 < 5/6 < 1
0
< 1/6 < 2/6 < 3/6 < 4/6 < 5/6 < 1
Number Lines can also help
to see how to
+ - x ÷
fractions.
I
0
I
¼
I
½
1/
4
I
¾
I
1
I
I
I
1¼ 1½ 1¾ 2
I
I
2¼
+ 1/4 + 1/ 4
¼ +¾ =1
because we start at ¼ and add (+) three ¼'s (or ¾)
to bring us to 1 whole
2
10
3
10
Two tenths plus
Three tenths
Five tenths which can be reduced by
dividing the numerator and denominator
by five to get ½.
+
=
5
7
12
16
16
16
+
3
=
4
+
16
16
+
6
16
=
+
7
16
=
3
16
=
9
16
When adding like fractions with the same
denominator, add the numerators only and
keep the same denominator.
1
1
2
+
=
3
3
3
1
1 = 2
+
6
6
6
3
8
4
+
8
7
=
8
1
1
4 + 4
2
=
4
6
1
7
+ =
8
8
8
3
5
8
=
+
9
9
9
2
1
3
+ =
4
4
4
2
2
4
+ =
5
5
5
When subtracting like fractions with the
same denominator, subtract the numerators
only and keep the same denominator.
2 3
8
9
- 6
9
1 = 1
3
3
= 2
9
-
2
3
1
3
1
3
3
1
4 - 4
2
=
4
7
1
6
=
8
8
8
3
2
1
=
3
3
3
2
1
1
=
4
4
4
4
2
2
=
5
5
5
Here's the situation. You have added the fractions
okay, but your answer may not be showing the
lowest equivalent fraction. So how do you make
sure when you are adding fractions that your
answer is shown in its lowest equivalent?
Let's use an easy example of adding
fractions so you will get the idea...
Notice that the original answer to adding the
fractions in our sample problem is "2/4." To find
out if our answer is in its simplest form, we must
factor the numerator and the denominator into
its prime numbers.
Prime numbers can only be divided by 1 and
itself. Factors are the numbers that when
multiplied together will equal that number.
What we are looking for are the prime numbers
that are common factors in both the numerator
and the denominator of a fraction. If we find
these common factors, we can then cancel them
out.
Since "2" is a common factor in both the
numerator and denominator of our example,
we will cancel out (1) one the 2’s in both the
numerator and denominator by dividing by
“2”.
Let's add a little tougher fraction to
be sure you've got it...
2
4
3
9
=
1
2
2
6
=
1
3
4
8
=
1
3
=
1
2