How to Multiply 4-Digit by 1-Digit Numbers Using Grid Method

TL;DR

To multiply a 4-digit number by a 1-digit number using the grid method, break the 4-digit number into its place values, multiply each part separately by the 1-digit number, and then add all the products together. For example, multiplying 6 by 7,981 results in 47,886 when using this approach.

Transcript

Let's multiply 6 times 7,981. And the way we're going to do it right now is just to represent or expand out 7,981 as 7,000 plus 900 plus 80 plus 1. And so multiplying 6 times 7,981 is the same thing as multiplying 6 times 7,000 plus 6 times 900 plus 6 times 80 plus 6 times 1. You'd essentially distribute the 6. And to help us keep track of things, ... Read More

Key Insights

• 💁 Expanded form breaks down a number into its place values for easier multiplication.
• ✖️ Mental multiplication techniques, such as expanded form, can be efficient in solving multiplication problems without the need for pen and paper.
• 💁 Adding the products of each part in expanded form multiplication is crucial for obtaining the correct final result.
• 💁 Understanding the steps involved in expanded form multiplication enhances overall mathematical comprehension.
• 💁 Expanded form multiplication can be used with numbers of varying sizes.
• ✖️ The technique of expanded form multiplication allows for mental calculation without relying on traditional multiplication methods.
• ✖️ Expanded form multiplication involves multiplying each part separately and then adding the individual products together.

Questions & Answers

Q: How can expanded form help in multiplying large numbers?

Expanded form breaks down a number into its place values, making it easier to multiply each part separately and then add the products together for the final result. It simplifies the multiplication process.

Q: What is the benefit of using mental multiplication techniques like expanded form?

Mental multiplication techniques, such as using expanded form, allow for quick calculations without the need for pen and paper. This technique promotes a deeper understanding of the multiplication process and can be useful in solving math problems mentally.

Q: Can expanded form be used for multiplying numbers of any size?

Yes, expanded form can be applied to multiply numbers of any size. It is particularly useful when dealing with larger numbers, as it breaks down the multiplication process into more manageable steps.

Q: Why is it necessary to add the individual products in expanded form multiplication?

Adding the individual products in expanded form multiplication is essential because it combines the partial results to determine the overall product. It merges the products of each place value to obtain the final answer.

Summary & Key Takeaways

• The video demonstrates how to multiply a larger number, 6, by 7,981 using expanded form.

• By breaking down 7,981 into thousands, hundreds, tens, and ones, the multiplication process becomes more manageable.

• After multiplying each part of the expanded form by 6, the individual products are added together to obtain the final result: 47,886.