7th Grade Math

Add and Subtract Integers

PART A B C D

Get ConnectED

Multi-Part

Lesson 2

GLE 0706.2.1

Extend understandings of

addition, subtraction,

multiplication and division to

integers. SPI 0706.2.5 Solve

contextual problems that

involve operations with

integers. Also addresses

GLE 0706.1.8, GLE 0706.2.2,

SPI 0706.2.1.

Subtract Integers

DOLPHINS At a local aquarium,

a popular attraction features

dolphins. Dolphins jump

through rings that are 5 meters

above the surface of the

water. To prepare, they start

from 6 meters below the

surface of the water. What

is the difference between the

two distances?

What do you need to find? the difference between the height of

the rings and the depth at which the dolphins start

Use counters to find 5 - (-6), the difference between the two

distances.

Place 5 positive counters on

the mat. Remove 6 negative

counters. However, there are

0 negative counters.

Add 6 zero pairs to the mat.

Now you can remove

6 negative counters. Find

the remaining number

of counters.

So, 5 - (-6)^ = 11. The difference between the two distances

is 11 meters.

Main Idea

Model subtraction of

integers.

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+ + + +

+ + + +

+

+ +

Lesson 2C Add and Subtract Integers 93

086_098_C2L2_895130.indd 93 12/29/09 4:00 PM