Library

IM: 7.5.13: Expressions with Rational Numbers (Lesson)

By Newsela Staff
Last updated 6 days ago
9 Questions
13.1: True or False: Rational Numbers
Decide if each statement is true or false. Be prepared to explain your reasoning.

(-38.76)(-15.6) is negative

10,000 - 99,999 < 0

(\frac{3}{4})(-\frac{4}{3})=0

(30)(-80)-50=50-(30)(-80)

13.2: Card Sort: The Same But Different
Your teacher will give you a set of cards. Group them into pairs of expressions that have the same value.
13.3: Near and Far From Zero
Complete the table and then answer the following questions related to the table.

For each set of values for a and b, evaluate the given expressions and record your answers in the table.

When a=-\frac{1}{2} and b=6, which expression:

-has the largest value?
-has the smallest value?
-is the closest to zero?

When a=\frac{1}{2} and b=-6, which expression:

-has the largest value?
-has the smallest value?
-is the closest to zero?

When a=-6 and b=-\frac{1}{2}, which expression:

-has the largest value?
-has the smallest value?
-is the closest to zero?

Are there any values could you use for a and b that would make all of these expressions have the same value? Explain your reasoning.

13.4: Seagulls and Sharks Again
A seagull has a vertical position a, and a shark has a vertical position b.

Use the applet to complete the activity below.

https://curriculum.illustrativemathematics.org/MS/students/2/5/13/index.html
[Scroll to the tool under "13.4: Seagulls and Sharks Again"]

In the applet, you may choose to start by clicking on the open circles on the seagull and shark to drag them to new vertical positions. Once you have them in place, drag each of the other animals to the vertical axis to show its position, determined by the expression next to it.
A dragonfly at d, where d=-b
A jellyfish at j, where j=2b
An eagle at e, where 4e=a
A clownfish at c, where c=\frac{-a}{2}
A vulture at v, where v=a+b
A goose at g, where g=a-b