Lesson 4 Standard Algorithm: One-digit and Multi-digit Numbers with Composing
Let’s use the standard algorithm to multiply one-digit numbers and multi-digit numbers.
Warm-up Number Talk: Partial Product
Find the value of each product mentally.
Activity 1 Compose with the Standard Algorithm
Here is how Han calculated
Here is how Elena calculated
What does the 2 in Elena’s calculation represent? Explain or show your reasoning.
What does the 5 in Elena’s solution represent? Explain or show your reasoning.
Activity 2 Use the Standard Algorithm
Calculate each product using Elena’s strategy.
Use the standard algorithm to find the value of