7th Grade Math

PARTPART A B CDCDE

2

Multi-Part

Lesson Add and Subtract Fractions

Get ConnectED

GLE 0706.2.2

Understand and work with

the properties of and

operations on the system of

rational numbers.

SPI 0706.2.1 Simplify

numerical expressions

involving rational numbers.

Also addresses GLE 0706.1.3,

GLE 0706.1.8, SPI 0706.2.3.

Main Idea

Use models to add

and subtract fractions

with unlike

denominators.

Unlike Fractions With Models

TELEVISION Half of Brandon’s class likes reality television best, and

_^1

5 of the class likes sports television best. What fraction of the class

likes either reality or sports television?

What do you need to find? what fraction of the class likes reality

or sports television

Model each fraction with fraction tiles.

1

2

1

2

1

5

1

5

To add, line up the end of the shaded part of the first

tile with the beginning of the second tile.

1

5

1

2

+^15

1

2

Test different fraction tiles below the model, lining up

each with the beginning of the first tile. Does the last

tile line up with the end of the second tile? If not, try

another tile.

Once the correct tile is found, shade the sections

between the beginning of the tile to the point where

they line up.

1

5

1

2

1

10

1

10

1

10

1

10

1

10

1

10

1

10

1

5

7

10

1

2

+

The marks

line up.

_^1

2

+ _^1

5

= _^7

10

So, _ 107 of the class prefer reality or sports television.

144 Rational Numbers

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