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IM: 7.5.3: Changing Elevation (Lesson)

By Newsela Staff
Last updated 3 months ago
17 Questions
3.1: That's the Opposite
Draw arrows on a number line to represent these situations:​

The temperature was -5 degrees. Then the temperature rose 5 degrees.

A climber was 30 feet above sea level. Then she descended 30 feet.

What's the opposite of each situation?

Running 150 feet east.

Jumping down 10 steps.

Pouring 8 gallons into a fish tank.

3.2: Cliffs and Caves
Explore the applet and then answer the questions.

https://curriculum.illustrativemathematics.org/MS/students/2/5/3/index.html

[Scroll to the tool under "3.2: Cliffs and Caves"]
A mountaineer is climbing on a cliff. She is 200 feet above the ground. If she climbs up, this will be a positive change. If she climbs down, this will be a negative change.

Complete the table.

Write an addition equation and draw a number line diagram for B. Include the starting elevation, change, and final elevation in your diagram.

A spelunker is down in a cave next to the cliff. If she climbs down deeper into the cave, this will be a negative change. If she climbs up, whether inside the cave or out of the cave and up the cliff, this will be a positive change.

Complete the table.

Write an addition equation and draw a number line diagram for C and D. Include the starting elevation, change, and final elevation in your diagram.

​What does the expression -45+60 tell us about the spelunker? What does the value of the expression tell us?

3.3: Adding Rational Numbers
Find the sums.

-35 + (30 + 5)

-0.15 + (-0.85) + 12.5

\frac{1}{2}+(-\frac{3}{4})

Are you ready for more?

Find the sum without a calculator.


10 + 21 + 32 + 43 + 54 + (-54) + (-43) + (-32) + (-21) + (-10)

3.4: School Supply Number Line
Your teacher will give you a long strip of paper.
Follow these instructions to create a number line.
  1. Fold the paper in half along its length and along its width.
  2. Unfold the paper and draw a line along each crease.
  3. Label the line in the middle of the paper 0. Label the right end of the paper + and the left end of the paper -.
  4. Select two objects of different lengths, for example a pen and a gluestick. The length of the longer object is a and the length of the shorter object is b.
  5. Use the objects to measure and label each of the following points on your number line.
  • a
  • b
  • 2a
  • 2b
  • a+b
  • -a
  • -b
  • a+-b
  • b+-a
Complete each statement using <, >, or =. Use your number line to explain your reasoning.
a _______ b
-a _______ -b
a + -a _______ b + -b
a + -b _______ b + -a
a + -b _______ -a + b