standard_description: Generate two numerical patterns using two given rules. Identify apparent relationships between corresponding terms. Form ordered pairs consisting of corresponding terms from the two patterns, and graph the ordered pairs on a coordinate plane. For example, given the rule “Add 3” and the starting number 0, and given the rule “Add 6” and the starting number 0, generate terms in the resulting sequences, and observe that the terms in one sequence are twice the corresponding terms in the other sequence. Explain informally why this is so.
problem_activity: Narrative
The purpose of this Number Talk is to elicit strategies and understandings students have for multiplying a one-digit number and a two-digit number, which will be helpful later in this lesson when students continue to practice multiplying within 100.
Launch
Display one expression.
“Give me a signal when you have an answer and can explain how you got it.”
1 minute: quiet think time
Activity
Record answers and strategy.
Keep expressions and work displayed.
Repeat with each expression.
Student Facing
Find the value of each expression mentally.
\(4\times10\)
\(4\times20\)
\(4\times21\)
\(4\times24\)
Student Response
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Activity Synthesis
“How did you figure out the more challenging products?” (Once I knew
\(4\times20\)
, I was able to build on it to find
\(4\times21\)
and
\(4\times24\)
by just adding more fours. I knew that 4 groups of 25 make 100, so I took away 4 to find 4 groups of 24.)


aligns: no