how do you multiply 512 x 46? those are really big numbers!

How do you multiply 512 x 46?

Those are really big numbers!

In this lesson you will learn how to multiply multi-digit

numbers by using the standard algorithm.

Let’s ReviewLet’s Review

Product – The result when two numbers are multiplied.

For Example:4 x 5 = 20

product

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Multiplication is repeated addition.

32 + 32 + 32 + 32 + 32

32 x 5 Multiplication is faster!

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Multiplying by powers of 10.

36 x 10 = 36036 x 100 = 3,600

36 x 1,000 = 36,000

Let’s ReviewA Common Mistake

Multiplying each digit as if it represents a number of “ones.”

It is important to remember the place value of each digit.

36 x 5 = 30 x 5 + 6 x 5

Let’s ReviewCore Lesson

Multiply 512 x 46

512x 46

First, we need to multiply 512 by

6.

Then we need to multiply 512

by 40.

Let’s ReviewCore Lesson

512x 46

2

1

7300

Adding a zero shows that we are

multiplying by 10’s.

8420+

23,552Next, we add the partial products.

Let’s ReviewCore Lesson

405x 57

5

3

3280

Adding a zero shows that we are

multiplying by 10’s.

5220+

23,085Next, we add the partial products.

2

In this lesson you have learned how to multiply multi-digit

numbers by using the standard algorithm.

Let’s ReviewGuided Practice

Multiply 422 x 18.

Let’s ReviewExtension Activities

Write a real world problem that could be solved by using 32 x 12.

Let’s ReviewExtension Activities

Every student received 24 pencils. If there are 20 students in my class, how many pencils did we have in all?

Let’s ReviewExtension Activities

Write a multiplication equation that has a product of 3,600.

Let’s ReviewQuick Quiz

Multiply 290 x 73.

Let’s ReviewQuick Quiz

Multiply 64 x 48.