6th Grade Math Textbook, Progress

Update your skills. See page 12.

Add Fractions

7-3

Felix tapes together horizontally three

pieces of paper. They measure 
 1

9

6


in.,


^78 
in., and 
^34 
in. How long is the

taped piece?

To find the length, n, of the taped piece,

add: 
 1

9

6 
in.

7

8 
in.

3

4 
in.n.

First estimate:

 196 

^78 

^34 
 
^12 
 1  1  2 
^12 
.

Then add.

To add fractions:


Find the least common denominator

(LCD) of the fractions.

Rename each fraction as an equivalent

fraction with the LCD as the denominator.

Add. Express the sum in simplest form.

The taped piece of paper is 2
 136 
in. long.


 1

9

6 


7

8





2


 2 
 1

9

6 

.
^78
.
^78 
^22 
^1146

.
^34
.
^34 
^44 
^1126

.
^34
.
43 
44 
^3156
 2
136

n 2 
 136 

3

4

7

8

9

16 in. in. in.

M

C

A

L

T

U

H

B

Think

The (LCD) of 
 196 
, 
^78 
, and 
^34 
is the

least common multiple (LCM) of

the denominators.

Multiples of 16: 16 , 32, 48, 64,...

Multiples of 0 8: 0 8, 16 , 24, 32,...

Multiples of 0 4: 0 4, 0 8, 12, 16 ,...

The LCD is 16.

Think

2 
 136 
is close to the

estimate of 2
^12 
.

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