Lesson 6 Standard Algorithm: Multi-digit Numbers with Composing

- Let’s multiply with the standard algorithm and compose new units.

Warm-up Number Talk: Three Factors

Find the value of each product mentally.

$(2 \times 3) \times 10$
$(2 \times 40) \times 10$
$(2 \times 200) \times 10$
$(2 \times 243) \times 10$

Activity 1 Compose a New Unit

Problem 1

Find the value of $241 \times 23$ .

Problem 2

Lin used the standard algorithm to find the value of $241 \times 23$ . Here is her work:

multiply. two hundred forty one times 23.

Where do you see $241 \times 3$ in Lin’s work?
Where do you see $241 \times 20$ in Lin’s work?
What does the 1 above 241 represent in Lin’s calculation?

Problem 3

Use the standard algorithm to find the value of $182 \times 41$ .
Use the standard algorithm to find the value of $304 \times 23$ .

Activity 2 All the Products

$647 \times 9$
$647 \times 50$
$647 \times 59$
$264 \times 38$

Practice Problem

Problem 1

Find the value of $562 \times 34$ using the standard algorithm.