standard_description: Recognize angles as geometric shapes that are formed wherever two rays share a common endpoint, and understand concepts of angle measurement:
- An angle is measured with reference to a circle with its center at the common endpoint of the rays, by considering the fraction of the circular arc between the points where the two rays intersect the circle. An angle that turns through 1/360 of a circle is called a “one-degree angle,” and can be used to measure angles.
- An angle that turns through n one-degree angles is said to have an angle measure of n degrees.
problem_activity: Narrative
This Number Talk encourages students to look for and use the structure of base-ten numbers and properties of operations to mentally find the value of division expression (MP7). The reasoning elicited here will be helpful later in the lesson when students find quotients of multi-digit numbers.
Launch
Display one expression.
“Give me a signal when you have an answer and can explain how you got it.”
Activity
1 minute: quiet think time
Record answers and strategy.
Keep expressions and work displayed.
Repeat with each expression.
Student Facing
Find the value of each expression mentally.
\(48 \div 3\)
\(480 \div 3\)
\(528 \div 3\)
\(5,\!280 \div 3\)
Student Response
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Activity Synthesis
“How is each expression related to the one before it?”
Consider asking:
“Who can restate _____’s reasoning in a different way?”
“Did anyone have the same strategy but would explain it differently?”
“Did anyone approach the problem in a different way?”
“Does anyone want to add on to _____’s strategy?”


aligns: no