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.

$3 \times 3$
$3 \times 20$
$3 \times 600$
$3 \times 623$

Activity 1 Compose with the Standard Algorithm

Here is how Han calculated $318 \times 3$ using partial products.

multiply. three hundred eighteen times 3.

Here is how Elena calculated $318 \times 3$ using the standard algorithm.

multiply. three hundred eighteen times 3 equals nine hundred fifty four.

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.

$3, 615 \times 4$
$16, 023 \times 3$
$27, 326 \times 3$
$10, 215 \times 6$

Practice Problem

Problem 1

Use the standard algorithm to find the value of $16, 452 \times 6$ .