Lesson 13Expressions with Rational Numbers
Learning Goal
Let’s develop our signed number sense.
Learning Targets
I can add, subtract, multiply, and divide rational numbers.
I can evaluate expressions that involve rational numbers.
Lesson Terms
- rational number
Warm Up: True or False: Rational Numbers
Problem 1
Decide if each statement is true or false. Be prepared to explain your reasoning.
is negative
Activity 1: Card Sort: The Same But Different
Problem 1
Your teacher will give you a set of cards. Group them into pairs of expressions that have the same value.
Activity 2: Near and Far From Zero
Problem 1
For each set of values for
Problem 2
When
has the largest value?
has the smallest value?
is the closest to zero?
Problem 3
When
has the largest value?
has the smallest value?
is the closest to zero?
Problem 4
When
has the largest value?
has the smallest value?
is the closest to zero?
Are you ready for more?
Problem 1
Are there any values could you use for
Activity 3: Seagulls and Sharks Again
Problem 1
A seagull has a vertical position
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
, where A jellyfish at
, where An eagle at
, where . A clownfish at
, where A vulture at
, where A goose at
, where
Print Version
A seagull has a vertical position
A dragonfly at
, where A jellyfish at
, where An eagle at
, where . A clownfish at
, where A vulture at
, where A goose at
, where
Lesson Summary
We can represent sums, differences, products, and quotients of rational numbers, and combinations of these, with numerical and algebraic expressions.
Sums:
Differences:
Products:
Quotients:
We can write the product of two numbers in different ways.
By putting a little dot between the factors, like this:
. By putting the factors next to each other without any symbol between them at all, like this:
.
We can write the quotient of two numbers in different ways as well.
By writing the division symbol between the numbers, like this:
. By writing a fraction bar between the numbers like this:
.
When we have an algebraic expression like