standard_description: Understand that a function is a rule that assigns to each input exactly one output. The graph of a function is the set of ordered pairs consisting of an input and the corresponding output. (Function notation is not required in Grade 8.)
problem_activity: Narrative
The purpose of this True or False is for students to demonstrate strategies they have for using equivalent fractions to add and subtract fractions with different denominators. These mental calculations prepare students for working with more complex common denominators during this lesson.
Launch
Display one statement.
“Give me a signal when you know whether the statement is true and can explain how you know.”
1 minute: quiet think time
Activity
Share and record answers and strategy.
Repeat with each statement.
Student Facing
Decide if each statement is true or false. Be prepared to explain your reasoning.
\(\frac{1}{4}+\frac{2}{4}=\frac{3}{4}\)
\(\frac{1}{2}+\frac{1}{4}=\frac{2}{4}\)
\(\frac{3}{4}-\frac{1}{2}=\frac{2}{4}\)
Student Response
Teachers with a valid work email address can
click here to register or sign in
for free access to Student Response.
Activity Synthesis
“How can we find the correct value of
\(\frac{3}{4}-\frac{1}{2}\)
?” (
\(\frac{1}{2}=\frac{2}{4}\)
so
\(\frac{3}{4}-\frac{2}{4}=\frac{1}{4}\)
.)


aligns: no