Warm-up Number Talk: The Value of the Digits
Find the value of each expression mentally.
Activity 1 Two Algorithms to Multiply
Here are two algorithms for finding the value of
Discuss with your partner:
How are Kiran’s algorithm and Diego’s algorithm alike? How are they different?
How do you think Kiran found the product 2,139?
Find the value of each product.
Activity 2 Algorithm Comparison
Analyze the two algorithms used to find the value of
How are Kiran and Diego’s algorithms alike? How are they different?
Where is the 12 in Kiran’s algorithm?
Try using Kiran’s algorithm to find the value of
Check your work using a different method.
Here is how Elena calculated the value of
Where does the 9 in Elena’s calculation come from? What about the 6?
Where do the 2 and the 1 in calculation come from?
Use Elena’s method to find the value of